IBM TS7700 Series Best Practices. Flash Copy for Disaster Recovery Testing V1.1.1

Transcription

1 7/9/2015 IBM TS7700 Series Best Practices Flash Copy for Disaster Recovery Testing V1.1.1 Norie Iwasaki, IBM STG, Storage Systems Development, IBM Japan Ltd. Katsuyoshi Katori, IBM STG, Storage Systems Development, IBM Japan Ltd. Takeshi Nohta, IBM STG, Storage Systems Development, IBM Japan Ltd. Joseph Swingler, IBM STG, Storage Systems Development, IBM USA Page 1 of 44

2 Contents 1 Change History Flash Copy for Disaster Recovery (DR) Testing Configurations Supported Code Requirements Restrictions Flash Copy DR Testing Common Terms Flash Copy for DR testing operation overview Basic steps for Using the Flash Copy for DR Testing Function General Considerations for the Flash Copy for DR Testing Function Operational Details Preparation Defining Write Protect Exclusion Categories Defining a Disaster Recovery Family Create a DR family or add a cluster to an existing DR family Remove a cluster from a DR family View status of a DR family Initiating the Flash Copy for DR Testing Enable the Write Protect Mode and the Flash Copy Disable the Flash Copy and the Write Protect Mode LIVECOPY Option Viewing flash delta data in cache from flash copies Flash Copy and the Management Interface (MI) Viewing delta amount of data in cache from flash copies using the Management Interface (nontape attached TS7720 cluster only) Viewing delta amount of data in cache from flash copies using the Management Interface (TS7720T cluster only) Viewing details of flash copy of logical volumes Virtual Tape Drives panel Write Protect mode panel Appendix A. Details of the format of data reported by DRSETUP library request command Supported keywords Format of the data reported by DRSETUP, ADD command Format of the data reported by DRSETUP, REMOVE command Format of the data reported by DRSETUP, WP, ENABLE command Format of the data reported by DRSETUP, WP, DISABLE command Format of the data reported by DRSETUP, FLASH, ENABLE command Format of the data reported by DRSETUP, FLASH, DISABLE command Format of the data reported by DRSETUP, DOALL, ENABLE command Format of the data reported by DRSETUP, DOALL, DISABLE command Format of the data reported by DRSETUP, LIVECOPY,FAMLIY command Format of the data reported by DRSETUP, SHOW command Page 2 of 44

3 1 Change History Version 1.0 Original version Version 1.1 Updates for TS7700 Release 3.2 Version Update the description on the automatic removal and Flash Copy on TS7720T Page 3 of 44

4 2 Flash Copy for Disaster Recovery (DR) Testing With release 3.1, concurrent disaster recovery testing is improved with the Flash Copy for Disaster Recovery Testing function. This enables a Disaster Recovery host to perform testing against a point in time consistency snapshot while production operations and replication continues. With Flash Copy, production data continues to replicate during the entire DR test and the same logical volume can be mounted at the same time by a DR host and a production host. Used in conjunction with Selective Write Protect for DR testing, DR test volumes can be written to and read from while production volumes are protected from modification by the DR host. All access by a DR host to write protected production volumes will be provided via a snapshot in time, or flash, of the logical volumes. In addition, a DR host will continue to have read access to production original content that has since been returned to scratch. In a real world outage, the point in time when the production environment becomes unavailable is not predictable, thus the state of the DR cluster or clusters is unpredictable with respect to volume consistency. Volumes may have not completed replication to a DR site or the replication for certain volumes may not have even started. Prior to the addition of Flash Copy for DR Testing, ongoing replication and remote grid access functionality could provide misleading DR test results. For example, if copies are not available, a DR host mount will simply access remote content through the grid. Also, a production volume which is modified via the production host has that modification carried over to the DR cluster or clusters. The Flash Copy capability mimics the consistency of one or more clusters at the DR site at time zero of a simulated disaster. Only the data consistent within the DR site at time zero is accessible to a DR test host. Some accounts accomplish this by pulling grid links. However, most customers require the production data to continue to replicate during the DR test so that in the event of a true disaster, all data is replicated as designed. During a DR test, volumes may need to be mounted from both the DR and production hosts. Prior to Flash Copy for DR Testing, these mounts were serialized such that one host access received an IN USE exception. This was especially painful when the true production host was the instance which fails the mount. Flash copy allows logical volumes to be mounted in parallel to a production host and a DR host. Production hosts may scratch volumes, reuse volumes or modify volumes but the DR TS7700 will provide a snapshot of the logical volumes from time zero of the simulated disaster event or the start of the DR test. 2.1 Configurations Supported The Flash Copy for DR testing function is supported on TS7700 Grid configurations where at least one TS7720 cluster exists within the DR location. The function cannot be supported under TS7740 only grids or where a TS7740 is the only applicable DR cluster. A TS7740 may be present and used as part of the DR test so long as at least one TS7720 is also present in the DR site. The TS7720 cluster in the DR location may be tape attached. 2.2 Code Requirements The Flash Copy for DR testing function was introduced with TS7700 code level release 3.1. All clusters in the grid must be running with R3.1 or higher microcode level to enable this function. Page 4 of 44

5 2.3 Restrictions There are a few restrictions for the FlashCopy function as following. Do not perform the DR testing using the Flash Copy function when a cluster in the grid is currently unavailable. An attempt to enable a flash copy in this situation will result in a failure. You can perform the DR testing using the Flash Copy function as long as all clusters in the grid are powered on (they can be in service/offline state as long as they are powered on). Do not perform the DR testing using the Flash Copy function when a cluster of which grid links are disconnected exists in the grid. Otherwise library request commands to enable write protect mode/flash copy will fail with an internal error. 2.4 Flash Copy DR Testing Common Terms The following terms are used throughout the document. Live Copy - A real time instance of a virtual tape within a Grid that can be modified and replicated to peer clusters. This is the live instance of a volume in a cluster which is the latest version of the volume on that cluster. If the Live Copy is also consistent relative to the grid, it can be altered via a production host or from a DR host when it s in the exclusion list of write protect. Flash Copy - A snapshot of a live copy at time zero (see below). The content in the flash copy is fixed and does not change even if the original copy is modified or if replication events occur. A flash copy may not exist at a particular cluster if a live volume was not present within that cluster at time zero. In addition, a flash copy does not imply consistency as the live copy may have been down level with respect to the grid or simply incomplete at time zero. DR Family -A set of TS7700 clusters (most likely those at the DR site) which serve the purpose of disaster recovery. One to seven clusters can be assigned to a DR family. The DR family is used to determine which clusters should be affected by a flash request and/or write-protect request via a Library Request (LI REQ) command. A DR Family of one TS7720 cluster is supported. The TS7720 cluster may be tape attached. Write Protect Mode (existing function) - When Write Protect Mode is enabled on a cluster, host commands fail if they are issued to logical devices in that cluster and attempt to modify a volume's data or attributes and that volume is not excluded from write protect. The flash copy is created on a cluster when it is in the write protect mode only. Also, only write protected virtual tapes are flashed. Virtual tapes assigned to the excluded categories are not flashed. Time Zero - The time when the flash copy is taken within a DR family. The time zero mimics the time when a real disaster happens. Customers can establish the time zero using a LI REQ command. TS7720T TS7720 tape attached cluster Page 5 of 44

6 3 Flash Copy for DR testing operation overview This chapter provides basic steps and general considerations for using the Flash Copy function. Details of the usage of library request (LI REQ) commands are provided later within this document. 3.1 Basic steps for Using the Flash Copy for DR Testing Function 1. Set up the write protection exclusion categories on each cluster to be added to a DR family using the TS7700 management interface (MI). Each cluster in the DR family must have identical exclusion categories defined. Do not enable write protect at this time from within the MI panel. If already enabled, it must first be disabled before moving to the next step. This step can be completed in advance of any DR test. 2. Define a DR family using a library request command. Note that the DR family is independent from cluster families for grid replication. A DR family is viewed as the cluster or clusters that make up a customer s DR site or sites. Essentially, the DR family is the group of clusters expected to be left running in the event of a production outage. This step can be completed in advance of any DR test. 3. Enable write protection for the defined DR family via an LI REQ command. This results in all clusters within the DR family enabling their pre-configured write protection state. This can be completed in advance of any DR test given many accounts prefer write protect be enabled indefinitely. Write protection enablement against a DR family must occur through the LI REQ command which is why any previously enabled write protection from within the MI must first be disabled as part of step To truly start the test or initiate a time zero snapshot, perform the Volume Flash of the volume repository within all TS7720 clusters in the DR family via an LI REQ command. When a Volume Flash occurs, all content in the TS7720 cache repositories within the DR Family perform snapshots creating an instant cloned point of isolation of the state of all volumes within TS7720 clusters in the DR location. Any changes to volumes from that point forward will be updated in the live file systems of the TS7720 clusters, while the original at time zero volumes remain unchanged. This function is carried out among all TS7720 clusters in a DR Family at the same time and is referred to as time zero. a. Note that only logical volumes which are in the cache repository are flashed when the LI REQ command was issued. Even on a TS7720T cluster this is true. Logical volumes are not in the cache repository but in a physical tape (a.k.a., migrated logical volumes) are not flashed. 5. Now, you can bring up your DR host environment and start DR test jobs accessing the clusters within the DR family. All host access will either reference the live version of the volume or the snapshot (flash copy) version based on the volume s category and the selective write protect exclusion definitions. This means host mounts to write protected volumes will access the snapshot (flashed instance) while write-protect excluded volumes will access live data. TVC selection of snapshot data will be limited only to those clusters in the DR family. If a TS7740 cluster or a TS7720T cluster exists in the DR family, its live content can be accessed only if no TS7720 has a snapshot instance and either the TS7740 or the TS7720T is shown to have had a copy prior to time zero *and* the LI REQ LIVECOPY usage option is set to "FAMILY" (the Page 6 of 44

7 default is NONE). Customers will need to activate the LIVECOPY option explicitly using a LI REQ command. If no cluster has a valid copy at time zero within the DR family, the DR host mount will fail. All mounts to a write protected volume at the DR cluster will result in a DR instance of ownership to be exchanged among peer clusters in a DR family. This will allow DR host mounts and live production mounts to occur in parallel. The parallel DR-Host ownership moves only among DR Family clusters and does not support advanced features such as Ownership Takeover. An attempt to modify a volume from a DR host which is in a write protected state will be denied. All flash copies are read only. TS7720 clusters in the DR family will see an increase in capacity requirements when snapshot volumes are reused in the production environment and then replicated to the DR site. These volumes will retain two instances (one at time zero and the latest production instance). Flash volumes which did not change throughout the DR test process do not utilize any additional capacity within a DR TS7720. Customers can check how much disk space is used for production modified flash copies via the management interface (cache utilization page) or the LI REQ command "CACHE" response. Customers can check whether a virtual tape device is mounting a flash copy or a consistent live copy via the management interface (virtual tape drives page). 6. Dissolve the flash copy of virtual tapes through a LI REQ command once the DR test completes. Any additional flash copy capacity is freed and given back to the TS7720 at this time. Page 7 of 44

8 3.2 General Considerations for the Flash Copy for DR Testing Function 1. The set of exclusion categories must be equal across clusters within a DR family. Otherwise, the LI REQ commands to enable write protect / enable flash copy will fail. The exclusion categories can be defined only using the management interface. No LI REQ command to define write protect categories is provided. 2. Be sure to add the write protection exclusion scratch categories to the list of fast ready categories on the DR clusters. If two scratch categories are defined on the DR host, both should be included in the write protect exclusion categories. z/os customers should add PRIVATE/ERROR category used by the DR host as well to the list of excluded categories (here it is required that the production host and the DR host use different categories for output volumes.) 3. A DR family is defined using an LI REQ command. The setting is persistent. 4. There must be at least one TS7720 in a DR family. The TS7720 cluster may be tape attached. A TS7740 can be a member of a DR family. However, you cannot create a DR family without at least one TS7720 being present. 5. All clusters within a DR family must be online to enable flash copy within the family. Other clusters in the grid can be offline or service state as long as they are powered on, grid links are working. 6. Volumes belonging to a TS7740 Cluster are not flash copied. Also, volumes in migrated state on a TS7720T cluster are not flash copied. 7. If the production host has connectivity to virtual tape devices on clusters included within the DR family, the tape devices must be varied offline from the production host. 8. Category mounts, category changes (including EJECT category) and construct changes initiated by a DR host to flash copies are not currently supported. They are failed with ERA29 mod X'10' or function incompatible. 9. All DR host activity must be issued to device ranges contained within the TS7720 clusters which are members of the defined DR family. Device ranges to any TS7740 within a DR family must be varied offline. 10. If no cluster has a valid copy at time zero within the DR family, the DR host mount fails. 11. All volume consistency points or recovery point objective testing against emulated outages or disasters is relative to when flash copy is enabled. All volumes not yet fully replicated to the DR site will not be accessible by the DR host as would be in a true outage. Any remote updates to DR site volumes will retain all updates up to that point in time. For example, if writes are occurring to a volume contained within a DR clusters tape volume cache and this FLASH command is issued, writes up to the point on tape in which the FLASH was issued will be accessible to the DR host and all records on tape from that point forward will not as would be true in an actual outage. 12. Tape Volume Cache selection of snapshot data is limited only to those TS7720 clusters in the DR family. 13. Flash copies within a DR family are not replicated to peer DR family clusters, though any real production instances or live copies will continue to replicate as configured. 14. If a TS7740 Cluster and/or a TS7720T Cluster exists in the DR family, its live content can be accessed only if no TS7720 Cluster in the DR family has a consistent snapshot instance and the TS7740 Cluster is shown to have had a copy prior to time zero. You must invoke an LI REQ command to enable the use of the live copy prior to starting the mount operation. This step permits the microcode to access live content on the TS7740 Cluster and/or the TS7720T Cluster Page 8 of 44

9 in the DR family when automatic removal is expected to have moved much of the oldest content into the TS7740. Or, when specific workloads are designed to bypass the TS TS7720 auto removal as well as the delete/expire processing will be disabled on all clusters which are members of a DR family that is currently in a snapshot state (note that this automatic disablement of these functions has no application to TS7720T cluster). This is because removal of volume content has no effect on the actual disk cache capacity given all content at time zero is retained. Temporary pre-removal is suggested prior to a DR test being initiated where automatic removal is required. Or, the lowering of the TS7720 automatic removal threshold be configured low enough to accommodate the entire test. As for how much the temporary removal should remove or how low the threshold should be lowered, it should account for all content that will replicate to the DR TS7720 during the entire duration of a DR test and for all content which will be created by the DR host during the entire DR test. The value should also take compression into account given all content in disk cache is compressed. 16. As described in the previous paragraph, the automatic removal policy is enabled by default for the CP0 or the resident only partition of a TS770T cluster. If the CP0 active and Flash Copy retained content crosses the auto removal boundary, the automatic removal can result in the excessive removal of the CP0 content when Flash Copy is enabled, so it s highly recommended that the automatic removal be explicitly disabled during a Flash Copy DR test. It can be disabled and then optionally re-enabled through the SETTING, CACHE, REMOVE, DISABLE LI REQ command. Refer to the IBM Virtualization Engine TS7700 Series z/os Host Command Line Request User s Guide on IBM techdocs website ( 03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/WP101091) for general information for the library request command. 17. The amount of Tape Volume Cache (TVC) used will increase within the DR family TS7720 clusters during the DR testing using the Flash Copy function. The increase will be limited to those production volumes which are reused given the reuse will result in two or more instances of the same volume within the TS7720 DR family clusters. Those volumes which are not modified during the test will require no additional TS7720 disk cache capacity. A TS7720 within a DR location will require additional capacity to accommodate the reuse of volumes as well as any DR test data which is created within an excluded category. This extra capacity requirement must be considered when planning the size of the TS7720 disk cache. In addition, if temporary pre-removal must take place, additional capacity can be purchased to accommodate a higher temporary removal threshold. 18. Return to scratch job may take longer to complete when flash copy is enabled somewhere in the grid. This is because a category change on a write protected logical volume after flash creation generates token snapshot of the logical volume on clusters within the DR family where flash copy is enabled. Page 9 of 44

10 4 Operational Details 4.1 Preparation Before setting up the actual DR testing environment with FlashCopy, make sure that all preparatory activities have been completed. These activities can be completed far in advance of an actual test and in many cases left in a configured state. 1. Determine the name of the DR family which you re going to create for the DR test. Only one DR family can be defined in a grid. Only alphanumeric characters can be acceptable as the name. No space must be included in the name. The maximum length of the name is 8 characters. 2. Determine what clusters in the grid are to be included in the DR family. IDs of clusters to be included in the DR family are required when you define the DR family in the grid (described in details in later within this document) 3. Determine write protect excluded categories to be defined for the DR test. For each z/os system plex attached to the DR Family clusters, the recommendation is to have each system plex's unique set of MEDIA1, MEDIA2, PRIVATE and ERROR categories defined within each DR cluster's exclusion category list. Excluding both MEDIA1 and MEDIA2 is required to accommodate workloads that can target either SCRATCH category. It's also recommended to include both MEDIA1 and MEDIA2 even if only one of the scratch categories are used within your environment. This is because any workload that does not explicitly use a defined data class with a defined scratch media type will result in mount requests that target both scratch categories. In this case, the TS7700 will fail the mount request if both category definitions are not excluded. The exclusion of the ERROR category can be optional. A volume can be moved to the ERROR category by z/os, but any user attempt to move it out of the ERROR category from a DR attached host will fail unless the ERROR category is also defined. 4.2 Defining Write Protect Exclusion Categories The Management Interface (MI) is used to define the logical volume categories that are excluded from write protection and thus can be created, modified or have their attributes changed from a DR host. Logical Volumes whose categories are not listed cannot be altered by the DR host(s). The Write Protect Exclusion categories need to be set up prior to starting the DR test. The MI panel for defining these categories is accessed by selecting (Settings) => Cluster Settings => Write Protect Mode. In the example below categories 0012, 001E, and 001F have been defined as the categories that will be used by the DR host. Be sure to set up the same excluded from write protect categories on all clusters in the DR family. The enabling of the DR test will fail when all clusters in the DR family do not have the same exclusion categories defined. Once the write protection command is executed, you are not able to change the settings of the write exclusion categories. If this is needed, the write protection (and the flash copy if enabled) needs to be disabled first. The Ignore fast ready characteristics of write protected categories option informs the DR cluster that production logical volumes defined as fast-ready (scratch) should be treated as private volumes. This means they will be presented to the DR host in their entirety in spite of them being set to a scratch category. This is only applicable to non-flash instances of the data such as when a TS7740 live copy must be accessed, which was previously returned to scratch and remains there. Any flash instances returned to scratch after time zero will always be accessible even when the production host reuses those Page 10 of 44

11 volumes. Any fast-ready categories that are included in the Write Protect Mode Exclusion Categories list will always be treated as scratch categories even when this option is enabled. The MI panel below also allows you to enable or disable Write Protect Mode. With Release 3.1 a new Library Request command (DRSETUP) is added that provides an alternate method to enable and disable the Write Protect mode. The MI panel can only enable or disable the standard write protect mode which is incompatible with the flash copy capability provided in the R3.1 release. It is required that the Library Request command be used to enable and disable write protect mode when used for the purpose of flash copy for DR testing. When flash copy for DR testing isn t going to be used, the LI REQ method can be used as an alternative to using the MI panel method as the resulting write protection behavior is the same. It s only when flash copy is going to be used where the two enablement methods have underlying differences in which the LI REQ enabled method is a pre-requisite to flash copy. This is discussed in a subsequent section. Figure 1 - Write Protect Mode Exclusion Categories Be sure to add the scratch categories to be used by the DR host, (0012 in the example above) to the list of scratch categories on all of the DR clusters. This panel is accessed on the MI by selecting (Virtual) => Categories. Notice that the Write Protect Mode is currently left disabled given it will be enabled via the LI REQ operation in a later step. Figure 2 - Scratch Categories Page 11 of 44

12 4.3 Defining a Disaster Recovery Family The Library Request Command DRSETUP is used to define which clusters are in a Disaster Recovery (DR) family. Only one DR family can be set up in a grid. The DR families must be set up prior to the actual DR testing using the Flash Copy function. Those clusters within a grid which are expected to remain running in the event of a production site outage should be defined within the DR family. There are three Library Request variants of the DRSETUP command used to manage DR families which are shown below. Refer to Appendix A for detailed format of the data reported by all the DRSETUP variants. Refer to the IBM TS7700 Series z/os Host Command Line Request User's Guide on techdocs for general information for the library request command Create a DR family or add a cluster to an existing DR family You can create a DR family or add a cluster to an existing DR family using the ADD keyword. The syntax of the command is: LI REQ, <clib_name>, DRSETUP, <family_name>, ADD, <cluster id> Where: <clib_name> is the composite library name of the TS7700 grid <family_name> is the eight character alphanumeric name for this family <cluster id> is the cluster index number 0-7 Note: The DR family is created the first time the DRSETUP, ADD command is issued when no family name of any value already exists. The DR family must be created using a TS7720 cluster. A family cannot be created using the ID of a TS7740 cluster. A TS7740 cluster can be added to an existing family once at least one TS7720 cluster exists in the existing family definition. The TS7720 cluster may be tape attached. You cannot add a cluster to a DR family when Write Protect is enabled. You cannot add a cluster to a DR family when Flash Copy is enabled. You cannot add a cluster to a DR family which is not in an online state. Following is an example of the command response when a DR family is newly created: CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,DRFAM001,ADD,1 DRSETUP V1.0 DR FAMILY DRFAM001 WAS NEWLY CREATED CLUSTER 1 WAS ADDED TO DR FAMILY DRFAM001 SUCCESSFULLY Following is an example of the command response when a cluster is added to an existing DR family CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,DRFAM001,ADD,3 Page 12 of 44

13 DRSETUP V1.0 CLUSTER 3 WAS ADDED TO DR FAMILY DRFAM001 SUCCESSFULLY Remove a cluster from a DR family You can remove a cluster from a DR family using the REMOVE keyword. The syntax of the command is: LI REQ, <clib_name>, DRSETUP, <family_name>, REMOVE, <cluster id> Where: <clib_name> is the composite library name of the TS7700 grid <family_name> is the eight character alphanumeric name for this family <cluster id> is the cluster index number 0-7 Note: The DR family definition is automatically deleted when the last member cluster is removed from the DR family. You cannot keep a DR family definition with no member cluster. Once the family is completely removed, a new family definition with the same or different name can be generated with the ADD keyword. The DR family must always include a TS7720 cluster. The last cluster to be removed from the family must be a TS7720. The TS7720 cluster may be tape attached. You cannot have a DR family which includes only a TS7740 cluster. You cannot remove a cluster from a DR family where Write Protect is enabled. You cannot remove a cluster from a DR family where Flash Copy is enabled. Following is an example of the command response when a cluster is removed from a DR family: CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,DRFAM001,REMOVE,2 DRSETUP V1.0 CLUSTER 1 WAS REMOVED FROM DR FAMILY DRFAM001 SUCCESSFULLY Following is an example of the command response when the last member cluster is removed from a DR family: CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,DRFAM001,REMOVE,1 DRSETUP V1.0 CLUSTER 1 WAS REMOVED FROM DR FAMILY DRFAM001 SUCCESSFULLY DR FAMILY DRFAM001 WAS DELETED BECAUSE NO MEMBER EXISTS Page 13 of 44

14 4.3.3 View status of a DR family You can view the current status of a DR family using the SHOW keyword. The syntax of the command is: LI REQ, <clib_name>, DRSETUP, SHOW [,<family_name>] Where: <clib_name> is the composite library name of the TS7700 grid <family_name> is the eight character alphanumeric name for the family to be shown. This is optional. If no family name is specified, then the summary view is displayed instead (currently only one DR family is supported). Following is an example of the command response when the SHOW command is issued to display the status of a DR family which includes two clusters: CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,SHOW,DRFAM001 DRSETUP V1.0 DR FAMILY VIEW ID FAM NAME FLASH FLASH TIME (UTC) LCOPY MEMBER CLUSTERS 1 DRFAM001 INACTIVE N/A NONE FAMILY MEMBER WRITE PROTECT STATUS VIEW CLUSTER WRT-PROTECT EXCATS-NUM IGNORE-FR ENABLED-BY CLUSTER0 DISABLED 4 TRUE N/A CLUSTER1 DISABLED 4 TRUE N/A CATEGORIES EXCLUDED FROM WRITE PROTECTION WITHIN DR FAMILY DRFAM001 CLUSTER ACTIVE EXCLUDED CATEGORIES CLUSTER F 001E CLUSTER F 001E The DR FAMILY VIEW displays the summary status of the specified DR family. The fields displayed in the line are as follows: ID: The ID of the DR family. Currently only one DR family can be defined in a grid. Therefore, the ID of the DR family is always 1. FAM NAME: The name of the DR Family FLASH: ACTIVE when FlashCopy is enabled within the DR family. INACTIVE when FlashCopy is not enabled. FLASH TIME: The UTC timestamp when the FlashCopy was enabled. N/A when the FlashCopy is not enabled. LCOPY: FAMILY when live copy usage is allowed within the DR family. NONE when live copy usage allowed. MEMBER CLUSTERS: IDs of clusters which are included in the DR family. Clusters not included in the DR family or non-existing clusters are displayed with -. Page 14 of 44

15 The DR FAMILY MEMBER WRITE PROTECT STATUS VIEW displays write protect status of each cluster in the DR Family. The fields displayed in each line are as follows: CLUSTER: The cluster included in the DR family. WRT-PROTECT: ENABLED when Write Protect is enabled on the cluster. DISABLED when Write Protect is not enabled. EXCATS-NUM: The number of write protect exclusion categories defined on the cluster. IGNORE-FR: TRUE when the Ignore fast ready characteristics of write protected categories option is enabled. FALSE when the option is not enabled. This option can be modified only through the Management Interface when write protection is disabled. ENABLED-BY: LIREQ when Write Protect is enabled via the DRSETUP LI REQ command. MI when Write Protect is enabled via the Management Interface. At the end of the DRSETUP, SHOW command response, you ll see the write protect exclusion categories defined on clusters included in the DR family. If the set of excluded categories does not match across clusters within the DR family and flash copy for DR testing is going to be used, you should utilize the MI and modify the appropriate clusters so that all clusters in the DR family are in agreement. The third keyword for the SHOW command is optional. You can issue the DRSETUP, SHOW command without family name. Following is an example of the command response when the SHOW command is issued without family name. CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,SHOW,DRFAM001 DRSETUP V1.0 DR FAMILY VIEW ID FAM NAME FLASH FLASH TIME (UTC) LCOPY MEMBER CLUSTERS 1 DRFAM001 INACTIVE N/A FAMILY NA N/A INACTIVE N/A NONE NA N/A INACTIVE N/A NONE NA N/A INACTIVE N/A NONE NA N/A INACTIVE N/A NONE NA N/A INACTIVE N/A NONE NA N/A INACTIVE N/A NONE NA N/A INACTIVE N/A NONE FAMILY MEMBER WRITE PROTECT STATUS SUMMARY VIEW CLUSTER STATUS ID FAM NAME C0 C1 C2 C3 C4 C5 C6 C7 1 DRFAM WR WR NA N/A NA N/A NA N/A NA N/A NA N/A NA N/A NA N/A Page 15 of 44

16 The DR FAMILY VIEW displays the summary status of the specified DR family as described in previous page. Although the response provides a total of eight rows only the first row will contain valid information. The other rows are reserved for future use. The FAMILY MEMBER WRITE PROTECT STATUS SUMMARY VIEW displays the summary of write protect status of clusters included in each family. Although this response also provides a total of eight rows only the first row will contain valid information. The other rows are reserved for future use. If the cluster is in write protect mode, it is shown as WR in the view. Page 16 of 44

17 4.4 Initiating the Flash Copy for DR Testing With the addition of Flash Copy for DR testing, there are now two main steps when initiating or concluding a DR test. This is enabling/disabling Write Protect mode and enabling/disabling the Flash Copy. The Write Protect mode prevents a DR host from modifying production volumes. This capability existed before R3.1. The Flash Copy defines a time-zero where any changes to logical volumes after that time are not seen by the DR host Enable the Write Protect Mode and the Flash Copy You can enable the Write Protect and Flash Copy using the LI REQ command either separately or in one command. The two operations must be issued sequentially where the WP keyword to enable the Write Protect Mode must be used before FLASH keyword to enable the Flash Copy. The write protection can be enabled ahead of any testing. As many accounts do, it can be left enabled indefinitely. One fact of leaving write protection enabled indefinitely is that any true outage where production actually fails over to the DR location would first require the write protection mode be disabled through the LI REQ command. This disablement would need to occur prior to running production at the DR location allowing true production volumes and their associated attributes to be modified. The syntax of the command using WP keyword is following: LI REQ, <clib_name>, DRSETUP, <family_name>, WP, ENABLE Where: <clib_name> is the composite library name of the TS7700 grid <family_name> is the eight character alphanumeric name for this family Note: You cannot enable the Write Protect Mode if it is already enabled on a cluster included in the DR family via MI or a previous LI REQ invocation. You cannot enable the write protect mode if the write protect exclusion categories don t match across all clusters included in the DR family definition. Write Protection can be enabled far in advance to the actual DR test. Following is an example of the command response when the Write Protect Mode is enabled: CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,DRFAM001,WP,ENABLE DRSETUP V1.0 WRITE PROTECT STATUS HAS BEEN ENABLED SUCCESSFULLY The DRSETUP, SHOW, <family> command now provides a response like following: CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,SHOW,DRFAM001 DRSETUP V1.0 DR FAMILY VIEW ID FAM NAME FLASH FLASH TIME (UTC) LCOPY MEMBER CLUSTERS 1 DRFAM001 INACTIVE N/A NONE Page 17 of 44

18 FAMILY MEMBER WRITE PROTECT STATUS VIEW CLUSTER WRT-PROTECT EXCATS-NUM IGNORE-FR ENABLED-BY CLUSTER0 ENABLED 4 TRUE LIREQ CLUSTER1 ENABLED 4 TRUE LIREQ CATEGORIES EXCLUDED FROM WRITE PROTECTION WITHIN DR FAMILY DRFAM001 CLUSTER ACTIVE EXCLUDED CATEGORIES CLUSTER F 001E CLUSTER F 001E Now that write protection is enabled through the LI REQ command or was previously enabled, you can issue the command to enable the Flash Copy which will mimic the time zero of a production site outage. The syntax of the command using FLASH,ENABLE keyword is following: LI REQ, <clib_name>, DRSETUP, <family_name>, FLASH, ENABLE Where: <clib_name> is the composite library name of the TS7700 grid <family_name> is the eight character alphanumeric name for this family Note: You cannot enable the FlashCopy if the Write Protect Mode is not yet enabled via the LI REQ enablement method within the DR family. All volume consistency points or recovery point objective testing against emulated outages or disasters is relative to when this command is issued. All volumes not yet fully replicated to the DR site will not be accessible by the DR host as would be in a true outage. Any remote updates to DR site volumes will retain all updates up to that point in time. For example, if writes are occurring to a volume contained within a DR clusters tape volume cache and this FLASH command is issued, writes up to the point on tape in which the FLASH was issued will be accessible to the DR host and all records on tape from that point forward will not as would be true in an actual outage. The command may take a few minutes to complete. You should verify the command response described below is recorded in the SYSLOG before you proceed to next step. Following is an example of the command response when the Flash Copy is enabled: CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,DRFAM001,FLASH,ENABLE DRSETUP V1.0 FLASH COPY HAS BEEN ENABLED SUCCESSFULLY You can verify if the Flash Copy and/or the Write Protect mode are enabled using the DRSETUP, SHOW command. The DRSETUP, SHOW, <family> command now provides a response like following: CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,SHOW,DRFAM001 DRSETUP V1.0 DR FAMILY VIEW ID FAM NAME FLASH FLASH TIME (UTC) LCOPY MEMBER CLUSTERS 1 DRFAM001 ACTIVE NONE Page 18 of 44

19 FAMILY MEMBER WRITE PROTECT STATUS VIEW CLUSTER WRT-PROTECT EXCATS-NUM IGNORE-FR ENABLED-BY CLUSTER0 ENABLED 4 TRUE LIREQ CLUSTER1 ENABLED 4 TRUE LIREQ CATEGORIES EXCLUDED FROM WRITE PROTECTION WITHIN DR FAMILY DRFAM001 CLUSTER ACTIVE EXCLUDED CATEGORIES CLUSTER F 001E CLUSTER F 001E An alternative option is to enable both the Write Protect Mode and the Flash Copy at the same time using the DOALL keyword. This method is provided for those accounts which do not require write protection be enabled in advance of the time zero snapshot. The syntax of the command using the DOALL keyword is as following: LI REQ, <clib_name>, DRSETUP, <family_name>, DOALL, ENABLE Where: <clib_name> is the composite library name of the TS7700 grid <family_name> is the eight character alphanumeric name for this family Following is an example of the command response when the Write Protect Mode and the Flash Copy are enabled with one command: CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,DRFAM001,FLASH,ENABLE DRSETUP V1.0 WRITE PROTECT STATUS HAS BEEN ENABLED SUCCESSFULLY FLASH COPY HAS BEEN CREATED SUCCESSFULLY Disable the Flash Copy and the Write Protect Mode When DR testing has completed and the snapshot is no longer needed, the disabling of Flash Copy and optionally the Write Protect mode can occur. The Flash Copy can be disabled by itself using the FLASH and DISABLE keywords. The Write Protect mode, which can be left enabled, is disabled using the WP and DISABLE keywords. If DOALL was used to enable both write protect and the flash copy, the two modes can be disabled independently. The syntax of the command using FLASH,DISABLE keywords is following: LI REQ, <clib_name>, DRSETUP, <family_name>, FLASH, DISABLE Where: <clib_name> is the composite library name of the TS7700 grid <family_name> is the eight character alphanumeric name for this family Note: You cannot disable the Flash Copy while a virtual tape device is mounting a flash copy volume. You need to demount the volume before disabling the Flash Copy. If the DR host is no longer available and therefore a demount is not possible, the virtual drives page of the MI can be used to force a demount of the mounted volume. Following is an example of the command response when the Flash Copy is disabled. Page 19 of 44

20 CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,DRFAM001,FLASH,DISABLE DRSETUP V1.0 FLASH COPY HAS BEEN DELETED SUCCESSFULLY The syntax of the command using WP,DISABLE keywords is following: LI REQ, <clib_name>, DRSETUP, <family_name>, WP, DISABLE Where: <clib_name> is the composite library name of the TS7700 grid <family_name> is the eight character alphanumeric name for this family Note: You cannot disable the Write Protect Mode while the Flash Copy is enabled in the DR family. You must disable the Flash Copy first. Following is an example of the command response when the Flash Copy is disabled. CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,DRFAM001,FLASH,DISABLE DRSETUP V1.0 WRITE PROTECT STATUS HAS BEEN DISABLED SUCCESSFULLY You can verify if the Flash Copy and/or the Write Protect mode are disabled using the DRSETUP, SHOW command. The SHOW command will provide an output like following when both the Flash Copy and the Write Protect Mode are disabled. CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,SHOW,DRFAM001 DRSETUP V1.0 DR FAMILY VIEW ID FAM NAME FLASH FLASH TIME (UTC) LCOPY MEMBER CLUSTERS 1 DRFAM001 INACTIVE N/A NONE FAMILY MEMBER WRITE PROTECT STATUS VIEW CLUSTER WRT-PROTECT EXCATS-NUM IGNORE-FR ENABLED-BY CLUSTER0 DISABLED 4 TRUE N/A CLUSTER1 DISABLED 4 TRUE N/A CATEGORIES EXCLUDED FROM WRITE PROTECTION WITHIN DR FAMILY DRFAM001 CLUSTER ACTIVE EXCLUDED CATEGORIES CLUSTER F 001E CLUSTER F 001E Both the Write Protect Mode and the Flash Copy can be disabled simultaneously using the DOALL and DISABLE keywords. The syntax of the command using these two keywords is following: LI REQ, <clib_name>, DRSETUP, <family_name>, DOALL, DISABLE Where: <clib_name> is the composite library name of the TS7700 grid <family_name> is the eight character alphanumeric name for this family Page 20 of 44

21 Note: TS7700 Flash Copy for Disaster Recovery Testing July, 2015 The command will disable write protect mode within the family and complete successfully if Flash Copy is not enabled yet with the family. Following is an example of the command response when the Write Protect Mode and the Flash Copy are disabled with one command: CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,DRFAM001,FLASH,ENABLE DRSETUP V1.0 FLASH COPY HAS BEEN DELETED SUCCESSFULLY WRITE PROTECT STATUS HAS BEEN DISABLED SUCCESSFULLY Page 21 of 44

22 4.5 LIVECOPY Option If a TS7740 cluster or a TS7720T cluster is present within a DR family, an option is available allowing the live copy on the TS7740/TS7720T cluster to be accessed so long as it completed replication or was otherwise consistent within the TS7740/TS7720T prior to time zero of the DR test. This is applicable if the TS7720 removed its copy or if the TS7740 was the only target of a volume. The option is disabled by default. You must explicitly enable the option using the library request command with LIVECOPY keyword as needed. The syntax of the command is following: LI REQ, <clib_name>, DRSETUP, <family_name>, LIVECOPY, FAMILY Where: <clib_name> is the composite library name of the TS7700 grid <family_name> is the eight character alphanumeric name for this family Note: You can use the option only if TS7740 cluster or TS7720T cluster is included in the DR family. You cannot use the option in a pure TS7720 (i.e., not tape attached) only DR family. Live copies contained outside of the DR family are not accessible as part of this option. Following is an example of the command response when the live copy usage is allowed. CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,DRFAM001,LIVECOPY,FAMILY DRSETUP V1.0 LIVE COPY USAGE HAS BEEN UPDATED TO FAMILY SUCCESSFULLY You can verify if the current LIVECOPY setting using the DRSETUP, SHOW command. The SHOW command will provide an output like following when the live copy usage is allowed. CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,SHOW,DRFAM001 DRSETUP V1.0 DR FAMILY VIEW ID FAM NAME FLASH FLASH TIME (UTC) LCOPY MEMBER CLUSTERS 1 DRFAM001 INACTIVE N/A FAMILY FAMILY MEMBER WRITE PROTECT STATUS VIEW CLUSTER WRT-PROTECT EXCATS-NUM IGNORE-FR ENABLED-BY CLUSTER0 DISABLED 4 TRUE N/A CLUSTER1 DISABLED 4 TRUE N/A CATEGORIES EXCLUDED FROM WRITE PROTECTION WITHIN DR FAMILY DRFAM001 CLUSTER ACTIVE EXCLUDED CATEGORIES CLUSTER F 001E CLUSTER F 001E You can disable the live copy option using the library request command with LIVECOPY,NONE keywords. The syntax of the command using the keywords is following: Page 22 of 44

23 LI REQ, <clib_name>, DRSETUP, <family_name>, LIVECOPY, NONE Where: <clib_name> is the composite library name of the TS7700 grid <family_name> is the eight character alphanumeric name for this family Following is an example of the command response when the live copy usage is disabled. CBR1280I Library VTSCOMP1 request. Keywords: DRSETUP,DRFAM001,LIVECOPY,FAMILY DRSETUP V1.0 LIVE COPY USAGE HAS BEEN UPDATED TO NONE SUCCESSFULLY Page 23 of 44

24 4.6 Viewing flash delta data in cache from flash copies The amount of Tape Volume Cache (TVC) used beyond normal day to day operations may increase within a DR family TS7720 cluster when the Flash Copy is enabled. One reason for this increase is because those TS7720 clusters must retain the snapshot image of virtual tapes at the time zero while allowing the live copy of the volumes to be modified. When a new copy arrives into the DR site, it will replace an existing live copy and thus the previous live copy is retained within the snapshot. This can result in up to a 2x increase per volume that is replicated where the volume had some previous version present at the time of the snapshot. You can check the amount of this retained delta data in cache from flash copies using a LI REQ command or the Management Interface. Refer to section 8.1 for viewing amount of data in cache from flash copies using the Management Interface. Starting with R3.1, the LI REQ CACHE response provides amount of data in cache from flash copies. An example of the CACHE response when the Flash Copy is enabled is as follows: Refer to the IBM TS7700 Series z/os Host Command Line Request User's Guide on techdocs for details of the CACHE response. CBR1280I Library VTSDIST1 request. Keywords: CACHE TAPE VOLUME CACHE STATE V4.0 TS7700 VIRTUALIZATION ENGINE MODEL: TS7720 TAPE ATTACH TOTAL INSTALLED/ENABLED GBS: / TOTAL ADJUSTED CACHE USED GBS: 9968 CACHE ENCRYPTION STATUS: CAPABLE OVERCOMMITTED CACHE PARTITIONS: NONE PRIMARY CACHE RESIDENT ONLY INFORMATION PRIVATE CACHE USED GBS: 7974 SCRATCH CACHE USED GBS: 1 CP ALLOC USED PIN PKP PRM COPY CPYT FLASH COPY INFORMATION INDEX ENABLED SIZE 1 YES NO 0 3 NO 0 4 NO 0 5 NO 0 6 NO 0 7 NO 0 8 NO 0 PRIMARY TAPE MANAGED PARTITIONS CP ALLOC USED PG0 PG1 PMIGR D_PMIGR COPY PMT CPYT " Page 24 of 44

25 Page 25 of 44

26 5 Flash Copy and the Management Interface (MI) Starting with R3.1, some management interface panels have changed to accommodate the introduction of the Flash Copy for DR testing function. 5.1 Viewing delta amount of data in cache from flash copies using the Management Interface (non-tape attached TS7720 cluster only) Starting with R3.1, the Cache Utilization panel of the Management Interface provides amount of data in cache retained due to flash copies. The MI panel for viewing the data is accessed by selecting (Monitor) => Performance => Cache Utilization => Total amount of data in cache. The following figure 3 shows an example of the cache utilization panel opened when the Flash Copy is enabled on the cluster. Figure 3: Total amount of data in cache from flash copies Page 26 of 44

27 5.2 Viewing delta amount of data in cache from flash copies using the Management Interface (TS7720T cluster only) Starting with R3.2, the Cache Partitions panel of the Management Interface provides amount of data in cache retained due to flash copies on TS7720T cluster. The MI panel for viewing the data is accessed by selecting (Monitor) => Performance => Cache Partitions => Properties for Resident Partition. Page 27 of 44

28 5.3 Viewing details of flash copy of logical volumes Starting with R3.1, the Management Interface Virtual Volume Details panel provides methods to view details about a volume s flash copy instance as well as a live copy of a logical volume. The MI panel for viewing details of a volume s flash copy is accessed by selecting (Virtual) => Virtual Volumes => Virtual Volume Details. If a flash copy for the volume exists, the Flash Copy field in the Virtual Volume Details table will have either Active or Created. If no flash copy for the volume exists, the Flash Copy field has Not Active. The Active state means that a flash copy for the volume exists and the volume properties have not been changed since flash copy was created. Following figure 4 shows an example of the volume details panel for a logical volume where a flash copy exists (but volume properties or volume content has not changed within the grid since the flash copy was created). Figure 4: Virtual volume details page (flash active ) Page 28 of 44

29 If a flash copy for the specified logical volume exists and the volume properties or content has been changed within the grid, the Flash Copy field of the Virtual volume details will have Created. The Created is a link to the Flash Copy Detail page which was newly introduced in R3.1. When you click on the Created link, you will be able to see the volume state at time zero. If only Active, the live and time zero properties are identical. Only when changes have occurred will the Created state surface which provides the ability to differentiate between the live copy and flash copy instance. Figure 5 shows an example of the volume details panel for a logical volume where a flash copy exists and the volume s properties have changed since the flash copy was created. Figure 5 shows volume properties of the live copy of the specified logical volume. Note that the live copy is now assigned to category 0001 (the Category field) which is a scratch category. When you click the Created link to view volume properties of the flash copy, you ll be redirected to the Flash Copy Detail page as shown in Figure 6. Figure 5: Virtual volume details page (flash created ) Page 29 of 44

30 The Flash Copy Details page shown in Figure 6 shows volume properties of the flash copy of the specified logical volume. Also the page provides information about the DR family which the flash copy belongs to and when the flash copy was created. Note that the flash copy is assigned to a private category 0x000F (see the Category field) although the live copy is now assigned to a scratch category as shown in the figure 5 in the previous page. Also note that only two clusters are included in the Cluster-specific Flash Copy Properties in figure 6 while all four clusters are shown in figure 5. This is because only two clusters are included in the DR family DRFAM001 in this example. Figure 6: Flash Copy Details panel Page 30 of 44

31 5.4 Virtual Tape Drives panel Starting with R3.1, the Virtual Tape Drives panel shows whether the mounted volume on a virtual tape drive is accessing a flash copy or live copy in the Mount Type column. Figure 7 shows an example of the Virtual Tape Drives page in R3.1. You can see a total of ten volumes are mounted and eight of those ten volumes are accessing a flash copy. Also, you can see all the flash copies are mounted as write protect (see the state field). Figure 7: Virtual Tape Drives panel Page 31 of 44

32 5.5 Write Protect mode panel If the flash copy function is active within a grid or the LI REQ method is used to enable write protect, write protect for flash copy information is displayed in the Write Protect Mode Panel as shown in Figure 8. The remainder of the page is grayed out (disabled) until a user disables the LI REQ enabled write protection. If any LI REQ enabled write protect is also not enabled, the page works as it originally did in R3.0 or prior code levels. This disablement is an enforcement of write protection needing to be exclusively enabled and disabled through the LI REQ mechanism when the intended purpose is assumed to be on behalf of flash copy for DR testing. If the LI REQ method is used to simply enable write protection and no intention of using flash copy is expected, the same disablement within the MI panel will remain under the assumption a flash copy may be enabled. Starting with R3.1, up to 32 excluded categories are supported for both MI and LI REQ enabled variations of write protection. Figure 8: Write Protect Mode Panel Page 32 of 44