PRIMERGY DuplexDataManager Help

Transcription

1 PRIMERGY DuplexDataManager Help DDM 5.01 help extraction November 17, 2010 Contents 1 OVERVIEW DuplexWrite Data Duplexing Dynamic Diskload Balancing DuplexWrite Group Data Recovery CloneData Event Logging MultiPath Failover Policy Error Recovery AutoFailback Automatic Load Balancing Path Monitoring Event Logging MPIO Error Handling, Failover and Recovery MPIO Dynamic Load Balancing HANDLE PRIMERGY DUPLEXDATAMANAGER Manage PRIMERGY DuplexDataManager Setting up a DuplexWrite Disk...11 Fujitsu Technology Solutions 2010

2 2.3 Breaking up a DuplexWrite Group Handle Disk Errors Microsoft Windows Clustering Support Setting up a RootDisk DUPLEXDATAMANAGER INSTALLATION Installation Uninstallation MMC SNAP-IN FOR DDM Node DuplexDataManager Node DuplexWrite Node DuplexWrite Group Node MultiPath Node MultiPath Group Node SCSI view Node SCSI port DUPLEXDATAMANAGER STATUS DuplexWrite Status MultiPath Status PROPERTY SHEETS DuplexDataManager DuplexWrite DuplexWrite Group...50 Fujitsu Technologie Solutions November 17, / 67

3 6.4 DuplexWrite Piece MultiPath MultiPath Group MultiPath Path SCSI Port SCSI Device TECHNICAL INFO How to find different paths to one disk How to find a DuplexWrite group System / Boot Partition COD Partition...67 Fujitsu Technologie Solutions November 17, / 67

4 1 Overview PRIMERGY DuplexDataManager (DDM) is the software solution for PRIMERGY servers which allow disk subsystems to be provided redundantly over large distances. It offers high availability in terms of connection and storage system failures. In combination with Microsoft Windows Clustering (MSCS) a full disaster-tolerant configuration can be set up. PRIMERGY DuplexDataManager combines two components: DuplexWrite mirrors data to an additional, remote storage MultiPath ensures redundant data paths to the disk storage units Currently there are two editions available: PRIMERGY DuplexDataManager : DuplexWrite and MultiPath PRIMERGY MultiPath: MultiPath only PRIMERGY MultiPath MPIO: Multi-path via Microsoft MPIO only 1.1 DuplexWrite DuplexWrite is the DDM component for data mirroring. DuplexWrite duplicates write operations so that two disks of different disk storages contain identical data. This solution is a so-called 'physical mirroring' because it is independent of logical data structures such as file systems. If one of the disks fails, DuplexWrite ensures that the data will continue to be processed smoothly by accessing the disk still in service. When the faulty disk has been repaired, data recovery can be done online while normal operation continues. No reboot is necessary. This applies to physical disks as well as complex RAID volumes. Even the system/boot disk (RootDisk) can be replaced online. The driver design is Microsoft Cluster Services (MSCS) compliant. Notes: DuplexWrite is not provided with product MultiPath. DuplexWrite only supports Basic Disks. DuplexDataManager/MultiPath does not run if any MPIO device specific module (DSM) is running on the system Data Duplexing DuplexWrite duplicates each write operation to both members of a DuplexWrite group. The DuplexWrite group appears to the operating system as one disk. Data is written to both disks as long as no error condition occurs. As a result, both disks of a DuplexWrite group contain identical data. Duplexing is done based on disk LUNs, including the virtual LUNs of a RAID subsystem. Fujitsu Technologie Solutions November 17, / 67

5 Data is read from one specified disk, called Preferred Disk. This disk can be selected from the DuplexWrite group. In case of an error - after a number of unsuccessful retries - the corresponding disk's status is set to Error and the disk will not be used, subsequently. The error is logged and a notification is sent to the user that this disk has been disabled. Configuration data and DuplexWrite states are stored on disk. DuplexWrite uses a special, non-standard partition for Configuration On Disk (COD) storage. User data remains unchanged and is stored on standard partitions. All (user) data is mirrored physically Dynamic Diskload Balancing Normally, DuplexWrite uses one disk for read, only. This disk - the Preferred Disk - can be chosen by the user. Dynamic Diskload Balancing means that read operations are distributed over both disks. A dedicated algorithm determines the best disk to read from. I/O speed increases because of less disk load per device increased cache hit ratio because of double disk cache faster seek times by optimal disk selection Therefore, Dynamic Diskload Balancing increases system performance compared to a non-ddm installation DuplexWrite Group A pair of redundant disks is called a DuplexWrite group. Both members (partner disks, pieces) of a DuplexWrite group contain identical (user) data. A DuplexWrite group appears to the operating system as one disk. Duplexing is done based on disk LUNs, including the virtual LUNs of a RAID subsystem. Each DuplexWrite group has one Preferred Disk - by default the first disk - where the data is read from. A group ID - optional a user defined name - identifies each DuplexWrite group. To avoid changes by mistake, a common unique key is assigned to both disks. This key is updated whenever a DuplexWrite group is created or a disk is deleted from a DuplexWrite group Data Recovery In normal operation both disks of a DuplexWrite group contain identical data. In case of an error the corresponding disk's status is set to Error and the disk will not be used, subsequently. All data is safe on the remaining partner disk. Before a disk can be returned to its DuplexWrite group, it has to be updated: All data has to be copied to the disk. This will be done online while normal operation continues. If a write operation occurs while data is recovered DuplexWrite synchronizes the write operation so that a consistent state is guaranteed. When the recover process has been finished successfully, the disk's status is set to Online, COD data is updated and the disk becomes a full functional member of the DuplexWrite group again. Fujitsu Technologie Solutions November 17, / 67

6 1.1.5 CloneData Use CloneData to copy the data of a DuplexWrite piece to a disk device (full snapshot). CloneData copies all data of a DuplexWrite piece (= source) to a dedicated destination device 'physically' (block based - not file based). To get a consistent copy, the source (one of the two DuplexWrite pieces) has to be disabled while copying. As the source piece has been disabled it has to be recovered when CloneData is finished. This recover can be started automatically. Delta Recover is recommended here. A special algorithm can be used to minimize DuplexWrite group's degradation time: In non-degraded mode (both pieces online) all blocks are copied once while all modifications during this phase are logged. In a second phase the source piece is disabled and all modified blocks are copied again - representing the state at disable time. The time of degradation is minimal - with the disadvantage of a non-predictable snapshot point in time. This algorithm is optional. The CloneData start time can be scheduled (once/daily/weekly). The CloneData task will only be created if the destination disk has no partitions or the partitioning is exactly identical to the source disk (DuplexWrite group). The COD partition will be copied but the partition type will be changed. CloneData does not change the operating systems disk signature on the destination disk. While CloneData is active the destination volumes (not at first time) will be locked. CloneData cannot start if the destination volume is in use. DuplexWrite makes up to four attempts to start a scheduled CloneData task. It is not required to connect the destination disk to a DuplexDataManager supported port. The port can be disabled for MultiPath or DuplexWrite functionality. It is recommended to run CloneData when the system load is low Event Logging All DuplexWrite driver events are logged by the standard system event logging. Additionally, the events are available to the Alarm Monitor of ServerView as SNMP traps. 1.2 MultiPath MultiPath is a component of the PRIMERGY DuplexDataManager and is the software for administering and operating redundant data paths. MultiPath ensures constant availability of the communication channel, even if disruptions occur on one of the connections. MultiPath requires at least 2 Fibre Channel host adapters per server with full cabling. MultiPath performs permanent monitoring of these connection paths, via which I/O data streams are transported from/to the disk storage unit. Even if a fault occurs on a data path such as failure of a FC host controller, or cable, hub or switch disruptions processing with the server is not interrupted. In such a situation, MultiPath switches to the second connection path and uses it for accessing the storage. The applications Fujitsu Technologie Solutions November 17, / 67

7 continue running without any disruption and the availability of the entire server installation is significantly increased. The driver design is independent on the underlying Fibre Channel host adapter. The design is not tailored to a specific storage. Support for special storage can be added easily. The driver design is Microsoft Cluster Services (MSCS) compliant. The Microsoft MPIO solutions are designed to work in conjunction with device specific module (DSMs) written by vendors. The package MultiPath MPIO provides the familiar MMC snap-in and the path monitoring via SNMP. Note: DuplexDataManager/MultiPath does not run if any MPIO device specific module (DSM) is running on the system Failover Policy Failover from one path to the other is initiated as soon as an error condition is detected. That error might be caused by a defect controller or cabling (typical: timeout). As reaction to one of these error conditions the MultiPath filter driver issues the following SCSI commands: Operating system special handling: Windows 2000: Windows 2003: Windows 2008: BUS RESET (as target reset is not fully implemented in Windows 2000) Send a LUN-Reset to the device. If the device does not support this, a Device-Reset is sent. If this is also not supported a BUS-Reset is sent. In Windows 2008, SCSI-Reservations are done by Persistent Reservation. To perform a failover of the path, a Preemption of the Persistent Reservation is done. TEST UNIT READY eventually a storage vendor specific command to switch LUNs to the desired port retry of the command on the other port Note: On FibreCAT CX storages the special command Trespass must be used to switch the active path to another Service Processor (SP) Error Recovery MultiPath implements an auto recovery feature, which automatically cleans up error conditions when for example a broken cable has been replaced. Fujitsu Technologie Solutions November 17, / 67

8 1.2.3 AutoFailback The MultiPath driver supports an AutoFailback mode: If this mode has been selected MultiPath will automatically failback to the Preferred path after error recovery. The Preferred path is selectable by the user. The Fujitsu FibreCAT SX MPIO DSM also supports AutoFailback, but the feature Preferred path is not supported. Only supported for Load Balance Policy Fail Over Only. Note: When AutoFailback is switched on, AutoBalance will be switched off Manual Load Balancing To enhance the data transfer rate the active paths of the MultiPath groups can be distributed across the available SCSI ports. To ensure that the distribution will be preserved over error situations or reboots the paths must be selected as Preferred paths and AutoFailback mode must be turned on. For MPIO see below. Note: When selecting the Preferred path the activation occurs on the first I/O to the device Automatic Load Balancing To enhance the data transfer rate the paths of the MultiPath groups will be automatically distributed across the available SCSI ports. Notes When AutoBalance is switched on, AutoFailback will be switched off. Not supported in Microsoft Cluster Server configuration. Not supported with MultiPath MPIO Path Monitoring If a MultiPath path is not available after a reboot, the MultiPath driver does not know it. To fix this gap the DuplexDataManager service compares the current MultiPath path configuration with the stored path configuration. The user stores/acknowledges the current MultiPath path configuration via the MMC snap-in menu 'Acknowledge Configuration'. The MultiPath path monitoring cycle time is 5 minutes by default. Missing paths are logged in the system event log, SNMP traps are generated and an error icon shows this state in the MMC snap-in Event Logging All MultiPath driver events are logged by the standard Windows event logging. Additionally, the events are available to the Alarm Monitor of ServerView as SNMP traps. Fujitsu Technologie Solutions November 17, / 67

9 1.2.7 MPIO Error Handling, Failover and Recovery The MPIO driver package, in combination with the vendor DSM, supports end-to-end path failover. The process of detecting failed paths and recovering from the failure, like load balancing, is automatic, extremely fast, and completely transparent to the IT organization. The data remains available at all times. Not all errors result in failover to a new path. Some errors are temporary and can be recovered using a recovery routine in the DSM; if recovery is successful, MPIO is notified and path validity checked to verify that it can be used again to transmit I/O requests. When a fatal error occurs, the path is invalidated and a new path is selected. To do this correctly, outstanding I/Os must be returned to a higher level in the stack. Once this is done, all devices on that path can be removed and then failed over to the new path MPIO Dynamic Load Balancing Load balancing, the redistribution of read/write requests for the purpose of maximizing throughput between server and storage device, is especially important in high workload settings or other settings where consistent service levels are critical. Without multipathing software, a server sending I/O requests down several paths may operate with very heavy workloads on some paths while others are underutilized. The Microsoft MPIO software supports the ability to transparently balance I/O workload, without administrator intervention. MPIO determines which paths to a device are in an active state and can be used for load balancing. Each vendor s load balancing policy (which may use any of several algorithms, such as round robin, the path with the fewest outstanding commands, or a vendor unique algorithm) is set in the DSM. This policy determines how the I/O requests are actually routed. If the DSM returns a path that is inactive, the failover process is initiated. Fujitsu Technologie Solutions November 17, / 67

10 2 Handle PRIMERGY DuplexDataManager 2.1 Manage PRIMERGY DuplexDataManager PRIMERGY DuplexDataManager provides two different user interfaces: Local or remote administration via Microsoft's Management Console (MMC). DuplexDataManager provides the MMC snap-in 'Configuration Snap-in' for administration. In the current ServerView version, the SNMP traps monitored. In addition, the status of the MultiPath MPIO SNMP agent processed in the ServerView Status Agent. Additional: The older ServerView version supports the graphical tree view of the MultiPath configuration. It can be accessed via ServerView's sub dialog Mass Storage > DDM View. For further information see ServerView's integrated help. To enter DuplexDataManager administration: Select entry 'Configuration Snap-in' from Start menu: Programs > Fujitsu > PRIMERGY DuplexDataManager. The Microsoft Management Console will show up with the snap-in 'DuplexDataManager'. Use the MMC node DuplexDataManager (local) for local administration. To manage a remote system: Right click on MMC node 'DuplexDataManager' and select 'Connect to another computer...' Follow the connect dialog... Use the MMC node DuplexDataManager (<host>) for remote administration. You must have host administrator rights to manage DuplexDataManager. Fujitsu Technologie Solutions November 17, / 67

11 2.2 Setting up a DuplexWrite Disk To set up a DuplexWrite disk proceed as follows: or Make sure to have a free partition entry and enough disk space for the COD. Enter MMC snap-in dialog DuplexDataManager. Select snap-in node SCSIView > SCSIPort. Select desired disk and click (right mouse button) menu action Create A dialog will show up: Enter a DuplexWrite group name. Select the location of the COD partition. Confirm creation of the DuplexWrite group. DuplexWrite initializes the COD partition. The status is Online. Make sure to have a free partition entry and enough disk space for the COD. Enter MMC snap-in dialog DuplexDataManager. Select snap-in node DuplexWrite and click (right mouse button) menu action Create A dialog will show up: Select desired disk and enter a DuplexWrite group name. Select the location of the COD partition. Confirm creation of the DuplexWrite group. DuplexWrite initializes the COD partition. The status is Online. In the dialog select where the Configuration On Disk (COD) partition will physically be located on disk. By default DuplexDataManager creates the COD at the beginning of mirrored space. In RootDisk group (system/boot disk) case the preferred location of the COD is at the end of the mirrored space. The DuplexWrite group is now available and can be used. User partitions can be created using Disk Management. To create the partner disk (2nd piece) proceed as follows: Use Disk Management to clean disk: remove all partitions or remove driver letters. All previous disk data will be destroyed! Enter MMC snap-in dialog DuplexDataManager. Select snap-in node DuplexWrite. Fujitsu Technologie Solutions November 17, / 67

12 Select desired DuplexWrite group and click (right mouse button) menu action Add A dialog will display a list of all available disks. Select a disk from the list. It will be added as second piece to the DuplexWrite group. The disk size must be equal or greater than the DuplexWrite group size. No user data will be affected. The new disk status is Error. Start Recover to set the second disk online. The second piece will set immediately online if the first piece is empty. A disk is empty, if there is no any partition is available except the DuplexDataManager COD partition. DuplexWrite supports Basic Disks, only. GUID partition table (GPT) Disks and Dynamic Disks are not supported. The disk layout/partitioning must be suited for DuplexWrite. Otherwise, the creation is rejected. DuplexWrite uses a primary partition to store the COD. The size of this partition is at least 32 MB. If there is no partition available, one primary partition must be deleted. If there is no space on the disk to create the COD, the partitions must be resized before setup. Do not delete a COD partition by Disk Management while DuplexDataManager is installed. This would lead to unpredictable errors! Delete a COD partition first by the DuplexWrite group command Delete Group. This will change the partition type from 'Healthy' to 'Unallocated'. In Microsoft Cluster (MSCS) installations shutdown the other node(s) before any configuration changes (e.g. create/add of DuplexWrite group). This avoids an inconsistent view of the storage resources. 2.3 Breaking up a DuplexWrite Group To break a DuplexWrite group: Use DuplexDataManager Configuration Snap-in for administration. Select Snap-in node for the DuplexWrite group Select the desired piece and click (right mouse button) menu action Disable. For RootDisks only the 2nd piece is selectable. Select it again and click (right mouse button) menu action Delete Piece. The old disk signature is deleted and the disk can be used as a normal disk again. In case of a RootDisk the master boot record (MBR) will be deleted. All user data is retained on the first piece. Applications will proceed without any disruption. Alternatively, one piece (disk) can be physically removed. Fujitsu Technologie Solutions November 17, / 67

13 2.4 Handle Disk Errors DuplexWrite disks are maintained by MMC snap-in node DuplexWrite Group. Use this snap-in entry to observe and change disk status. Detailed disk information is available by double clicking on the desired disk entry (submenu Properties). This section describes different error situations and the recommended user action. One piece is in status Error: All data can be recovered from the partner disk: Select piece with DuplexWrite status Error and click (right mouse button) menu action Recover. In case of a disk hard error exchange the defect disk first. If the disk is hot swappable this can be done online. Make sure that the replacement disk has the appropriate size. One piece is missing: When the failing disk (LUN) has been removed it is still known from the COD data of the partner disk - even after a reboot. It will subsequently be listed as missing. Before a new disk (LUN) can be added to the current DuplexWrite group the missing entry has to be deleted: Select piece and click (right mouse button) menu action Delete Missing Piece. The attribute missing will be deleted. Now, a new disk can be added by menu action Add. Both pieces are in status Error: When both disks are in status Error the DuplexWrite group is not available to the application anymore. From operating system point of view this situation shows up like a disk failure. Further reaction depends on the application. DuplexWrite ensures that all data written previously to this double-error situation is safe. Choose the disk with the most recent data for data retrieval. Open Properties for both pieces to get the information on last update. Find most recent disk (flag Recent set), select it and click (right mouse button) menu action Online. This will set the selected piece Online. Now select the other (not most recent) piece and click (right mouse button) Fujitsu Technologie Solutions November 17, / 67

14 menu action Recover. The DuplexWrite status of this piece will change to Recover, later on to Online. Now, proceed as described for one disk in status Error (see above). In case of MS cluster configurations be aware of misinterpretation of shown data (see section on MS Clustering Support for more information). 2.5 Microsoft Windows Clustering Support The Microsoft Windows Clustering (MSCS) provides additional host failure tolerance and can be combined with DuplexWrite and/or MultiPath to achieve full disaster-tolerance. Even if DuplexWrite uses a duplexing method, which is transparent to the application, special handling for MSCS is necessary: Disks are shared among cluster nodes. The configuration data and states can be changed by another node. MSCS uses the SCSI commands RESERVE and RELEASE. A reserve command makes a disk inaccessible for all other nodes. DuplexDataManager uses the MS cluster service to get further information. This enables DuplexWrite to get additional information on shared disks that are currently assigned to another node. Following example demonstrates the effects of SCSI reservation: Consider a cluster system composed of two nodes A and B. Both pieces of the shared DuplexWrite group are currently assigned to node A. Because of the SCSI reservation these disks cannot be read from node B. The COD data is inaccessible. Because of the DDM cluster service these disks are known and listed as cluster resources. When DuplexDataManager has problems connecting to the MS cluster service both pieces will appear to node B similar to defect DuplexWrite disks. DuplexWrite group as seen from node A; 2nd disk currently recovering: Same DuplexWrite group as seen from node B; disks already known to DuplexWrite as configured for MSCS: If a disk is reserved by another cluster node only SCSI bus information is available. The configuration data, even disk sizes cannot be obtained. Use the SCSI bus information for disk identification. Fujitsu Technologie Solutions November 17, / 67

15 When the second cluster node has finished booting it is possible that some DuplexWrite disks or even DuplexWrite groups are not displayed. This can be overcome by moving all cluster resources from the first node to the second node. Be aware of misinterpretation of shown data, especially when both pieces are in status Error, like: Check other node's view first. It must show both pieces like: Otherwise, cluster communication is broken, or MMC snap-in data needs to be refreshed. After booting a cluster node move all disk resources once to all cluster nodes so that DuplexWrite takes over the DuplexWrite configuration. If Refresh or Rescan does not show the correct data, the DuplexDataManager Service should be restarted. After restarting the Cluster Service the DuplexDataManager Service must be restarted too. MSCS is a high available cluster solution - not a fault tolerant solution. For this reason the default behavior for DuplexWrite is to continue operation even if one piece of a DuplexWrite group is missing. If all interconnects (network and storage) between the clusters nodes are broken, it is, in principle, possible, that two half s of an MSCS configuration will continue operating. Take this into consideration when planning your cabling. On the other hand DuplexWrite can be configured to prevent access to a DuplexWrite group if one piece is missing - ask for support if you want to use this feature. 2.6 Setting up a RootDisk DuplexDataManager supports mirroring of the system/boot disk. This special DuplexWrite group is named RootDisk. When preparing the system/boot disk due operating system installation a free area at the end of the disk must be reserved. Requirements: The partition size is aligned according to disk's geometry and thus can be larger than COD's minimal space requirement of 32 MB. We recommend 39 MB as minimum. The COD partition uses a free primary partition. Fujitsu Technologie Solutions November 17, / 67

16 Restrictions: Mark the second LUN (mirror) in controller BIOS as boot LUN. In MultiPath case there are four entries (Destination Identifier (D_ID), Host Bus Adapter WWPN, and Storage Controller/Port WWPN) marked as boot LUN. For DuplexWrite RootDisk mirroring the system and boot partitions must be on the same disk. It is only possible to create DuplexWrite RootDisks on supported controllers and storages. To set up a DuplexWrite RootDisk group proceed as follows: Install the operating system (see requirements). Install the DuplexDataManager package and restart the system. Enter MMC snap-in dialog DuplexDataManager. Select snap-in node DuplexWrite and click (right mouse button) menu action Create. A dialog will show up: Select desired disk and enter a DuplexWrite group name. Choice the location of the COD partition at the end of the mirrored space. Confirm to create the DuplexWrite group. DuplexWrite initializes the COD partition. The procedure to add the second disk is described in Setting up a DuplexWrite disk. The DuplexWrite RootDisk group is featured with '[root] (System)' in the MMC snap-in. DuplexDataManager filter driver ddm.sys: On system start all drivers will be loaded. ntkrnlpa.exe hal.dll... ACPI.sys WMILIB.sys PCI.sys isapnp.sys ddm.sys... ftdisk.sys... storport.sys... Before ddm.sys is loaded, the system reads from the boot disk. Until that time there are no writes on the disk. When ddm.sys is loaded all reads and writes are managed via DuplexDataManager. Fujitsu Technologie Solutions November 17, / 67

17 Special restriction for DuplexWrite RootDisk group: DuplexWrite does not know from which disk/path the system is booted. Normally the first piece/disk of the RootDisk is the boot disk. If this piece does not have has a DuplexWrite status unequal Online (Error or Disabled), the system will boot on this degraded disk (if it is readable) before ddm.sys is loaded. Please ensure that the system boots from an Online disk. If a disk was prepared accidentally use Disk Manager to clear the disk drive. Otherwise, do not modify the COD partition with OS-unknown type! Do not upgrade to Dynamic Disk. DuplexWrite supports Basic Disks, only. Please refer for the currently released settings of the fibre channel switches, host bus adapters and storages. 3 DuplexDataManager Installation PRIMERGY DuplexDataManager (DDM) software comes on CD medium. Updates are available on Fujitsu Technology Solutions download web side. 3.1 Installation The DuplexDataManager installation procedure: Be sure to have administrator rights. Insert CD-ROM 'PRIMERGY DuplexDataManager', 'PRIMERGY MultiPath' or 'PRIMERGY MultiPath MPIO'. Change to 'CD-ROM:\Packages\Windows' directory. In MPIO case 'CD- ROM:\Windows' Use setup*.msi to install the software. Follow the Installation Wizard. Reboot the system after successful installation (only if a reboot is required). For remote administration with the MMC snap-in it is sufficient to install the client (frontend) only: Deselect (uncheck) Service installation in wizard feature dialog. DuplexDataManager may require some special settings for the host bus adapter and the RAID storage. Please, check the Readme file. For remote monitoring (e. g. ServerView) the DuplexDataManager SNMP agent will be installed. In the program directory of the DuplexDataManager service component a MIB (Management Information Base) can be found. This MIB describes all DuplexDataManager management information (traps,...). Fujitsu Technologie Solutions November 17, / 67

18 3.2 Uninstallation Because DuplexWrite disks are true duplicates, the operating system may be confused seeing the same disk signature twice when DDM is not active. Therefore, all DuplexWrite groups must be broken up. For more information, see Breaking up a DuplexWrite Group. Alternatively, one piece (disk) can be physically removed. When all DuplexWrite groups have been broken up (deleted) DuplexDataManager can be uninstalled. Use the standard software uninstallation procedure to remove DuplexDataManager: Choose 'Add/Remove Programs' from the Control Panel. Choose 'Fujitsu PRIMERGY DuplexDataManager ', 'Fujitsu PRIMERGY MultiPath' or 'Fujitsu PRIMERGY MultiPath MPIO' from the list of installed software. Click button 'Remove'. Reboot the system after successful uninstallation. Not needed in 'Fujitsu PRIMERGY MultiPath MPIO' case. 4 MMC Snap-in for DDM DuplexDataManager provides the MMC snap-in 'Configuration Snap-in' for administration. 4.1 Node DuplexDataManager MMC entry to manage PRIMERGY DuplexDataManager. It contains the views: DuplexWrite MultiPath SCSI View DuplexWrite is not provided with MultiPath! The host name is shown within brackets. e. g. DuplexDataManager (local) Fujitsu Technologie Solutions November 17, / 67

19 Action on DuplexDataManager node (right mouse button) Connect to another computer... Refresh Rescan devices Select the computer you want DuplexDataManager to manage. Refresh all MMC information. Recommended in case of failure situation to be sure that shown status is the current one. Rescan SCSI bus for changes/new devices. This command may have unwanted effects because it restores the current view of the SCSI bus: For instance a defect MultiPath connection (path) will be deleted from this view and will not be available further on! Use this command to overcome suspicious device states, only. Open archive... Open an archived DuplexDataManager configuration file. An archive can be used to monitor configuration changes and can help customer support in maintenance cases. In archive mode only a restricted set of operations is available. Archive... Archive the current DuplexDataManager configuration into a file. An archive can be used to monitor configuration changes and can help customer support in maintenance cases. Only accessible if a connection to a computer exists. To archive the configuration into a text file use the DuplexDataManager command line utility ddmutil.exe (e.g. ddmutil -ddm -l > filename.txt). Set DuplexDataManager notification... Set DuplexDataManager notification on server console. Affects system tray icon on the server. Enable system tray icon on server console: Select to display the DuplexDataManager system tray icon on server console. View icon in degraded/error state only: Select to display the DuplexDataManager system tray icon only when DuplexDataManager detects degraded or erroneous groups. 'View icon in degraded/error state only' only selectable if 'View icon in degraded/error state only' is enabled. Only accessible if a connection to a computer exists. Enter Product Key... Enter the DuplexDataManager Product Key. You will find this number in the License Paper. Only accessible for DuplexDataManager and no valid Product Key entered before. Fujitsu Technologie Solutions November 17, / 67

20 View Product Key... View the DuplexDataManager Product Key. Only accessible for DuplexDataManager and a valid Product Key entered before. Properties Help Show detailed information on DuplexDataManager drivers and services. Open MMC's help facility. 4.2 Node DuplexWrite MMC entry to manage DuplexWrite (not provided with MultiPath). The result pane shows information on all DuplexWrite groups. Status dependent icons Normal Open/Selected Disabled Recover Error CloneData Disk is Offline Disabled (hidden): A duplicate signature was detected on a disk. Action on DuplexWrite node (right mouse button) Refresh Create... Refresh all MMC information. Recommended in case of failure situation to be sure that shown status is the current one. Create a new DuplexWrite group: Dialog will display a list of all available non-duplexwrite disks. Select a disk and input the new DuplexWrite group name. Select where the Configuration On Disk (COD) partition will physically be located on disk. - DuplexWrite initializes the COD partition/blocks. - The DuplexWrite group is now available and can be used. No user data will be affected. On a system mirror (RootDisk) the RootDisk flag will be set automatically. Fujitsu Technologie Solutions November 17, / 67

21 In MSCS installations shutdown the other node(s) first to avoid an inconsistent view of the storage resources. The disk layout/partitioning must be suited for DuplexWrite. Otherwise, the command is rejected. Set Recover Mode... Mode to be used for recovery. Affects all DuplexWrite groups. Verify: [default] Read from both disks, compare and write if necessary (fast policy if disks are slightly different). Copy: Read from online disk and write to the second one (best policy if disks are completely different). Delta: Recover only delta areas since failure (fastest policy if disks are slightly different). Do not use Delta Recover when the disk to be recovered has been modified externally since failure (e.g. by another server or by exchanging one disk of a RAID group). Recover All... Recovers all DuplexWrite groups, which have status Error. A dialog displays two options to start the process: Immediate: [default] Start process now. Timer: Select date and time when the process should start. Process start time will be checked every 5 minutes, only. Selectable if at least one piece of a DuplexWrite group has status Error. Enable/Disable Diskload Balancing Set Dynamic Diskload Balancing On/Off. Affects all DuplexWrite groups. On: Both disks of a DuplexWrite group are used for read. A special load balancing algorithm determines best disk to read from. The Prefer flag has no effect. Off: No load balancing, read from preferred disk. Delete Delete all CloneData inactive tasks and information. CloneData tasks Selectable if at least one CloneData task is available where CloneData is not active. Prefer All... Disable All... Prefer all DuplexWrite pieces with the same Unit Serial Number (assume one storage). Not all storages support a unique Unit Serial Number for all drives (e.g. FibreCAT SX). Disable all DuplexWrite pieces with the same Unit Serial Number (assume one storage). Not all storages support a unique Unit Serial Number for all drives (e.g. FibreCAT SX). Fujitsu Technologie Solutions November 17, / 67

22 Enable/Disable Autostart Recover Set Autostart Recover On/Off. Affects all DuplexWrite groups. On: Every minute the status of all DuplexWrite groups will be checked. The DuplexWrite status and the reason of the error piece will be checked. If it makes sense a recover will be started. This action is monitored and a start recover is limited to 3 tries per DuplexWrite group. At next system start this counter will be cleared. In the case of a DuplexWrite missing piece - Online (one missing) or Online Error with corresponding reason a rescan will be started to get the lost device or the current status of the device. In some cases a recover can not be started or make no sence. For this issue a resan make sense before a recover will be started. A rescan started for DuplexWrite groups with a missing piece and DuplexWrite groups with an error piece and reason: DW_REASON_READ_FAILED - Read error DW_REASON_WRITE_FAILED - Write error DW_REASON_WRITE_CONFIG_FAILED - COD could not be updated on disk DW_REASON_READ_CONFIG_FAILED - COD could not be reread DW_REASON_PNP_REMOVE - Plug and Play remove request caused piece to be set to Error A recover started for DuplexWrite groups with two pieces with Status Online Error and the Error piece with following reason: DW_REASON_READ_FAILED - Read error DW_REASON_WRITE_FAILED - Write error DW_REASON_TIME_OUT_OF_SYNC - Piece disabled because timestamp was older than that of the other one DW_REASON_WRITE_CONFIG_FAILED - COD could not be updated on disk DW_REASON_READ_CONFIG_FAILED - COD could not be reread DW_REASON_RECOVER_READ_FAILED - Data could not be read during recover process DW_REASON_RECOVER_WRITE_FAILED - Data could not be written during recover process DW_REASON_SIGNATURES_ARE_WRONG - Signatures of both pieces of the DuplexWrite group are not the same DW_REASON_WRITE_FLAG - Data is inconsistent - COD could not be synced after last write No automatically recover started: DuplexWrite status Error which is set by user will not processed. A recover is pending. Off: [default] No Autostart Recover is enabled. Properties Help Show detailed information on DuplexWrite. Open MMC's help facility. Fujitsu Technologie Solutions November 17, / 67

23 Information on DuplexWrite group(s) The DuplexWrite group data may not be up to date if the resource is owned by other cluster node (status Cluster). Name DuplexWrite group name. This name can be chosen on group creation. The associated MultiPath group IDs are optionally shown within brackets. Additional attributes: [root]: Selected group is prepared as RootDisk (RootDisk flag set). (System): Selected group is system disk. System and boot disk must be the same. (Boot): Selected group is boot disk. Not supported! Group DWrite Size DuplexWrite group ID. Defined by DuplexWrite. Effective size of the DuplexWrite group in Mbytes (including COD). This size may be smaller than the disk's real size because of previous size adjustments to a smaller DuplexWrite group. Recover Mode Mode to be used for recovery. Verify: [default] Read from both disks, compare, and write if necessary (fast policy if disks are slightly different). Copy: Read from online disk and write to the second one (best policy if disks are completely different). Delta: Recover only invalid areas since failure (fastest policy if disks are slightly different). Copy (Delta): In this case the recover mode is changed from Delta to Copy because the delta mode cannot be used (e.g. first recover or error during recover). The recover mode is switched from Delta to Verify for the duration of the recovery in cases where DuplexWrite knows that the differences between the pieces are minimal but where no delta information is available. This happens if COD could not be synced after last WRITE. Settable in DuplexWrite Group Diskload Balancing Dynamic Diskload Balancing mode. On: Both disks of a DuplexWrite group are used for read. A special load balancing algorithm determines best disk to read from. The Prefer flag has no effect. Off: [default] No load balancing, read from preferred disk. Fujitsu Technologie Solutions November 17, / 67

24 -: No mode selected. Group is degraded and consists of only 1 piece. Settable in DuplexWrite Group Owner Owning cluster node of the resource. <cluster node>: Cluster node name. local: Local DuplexWrite group which is not used as cluster resource. If no cluster service is running the owner is local. This column is available in cluster environment only. Drive Letter(s) Drive letters assigned to the disk partitions. Action on selected DuplexWrite group (right mouse button) Refresh Set Recover Mode... Refresh all MMC information. Recommended in case of failure situation to be sure that shown status is the current one. Mode to be used for recovery. Affects selected DuplexWrite group. Verify: [default] Read from both disks, compare and write if necessary (fast policy if disks are slightly different). Copy: Read from online disk and write to the second one (best policy if disks are completely different). Delta: Recover only invalid areas since failure (fastest policy if disks are slightly different). Do not use Delta Recover when the disk to be recovered has been modified externally since failure (e.g. by another server or by exchanging one disk of a RAID group). Selectable only for Online DuplexWrite groups. Enable/Disable Diskload Balancing Set Dynamic Diskload Balancing On/Off. Affects selected DuplexWrite group. On: Both pieces of a DuplexWrite group are used for read. A special load balancing algorithm determines best piece to read from. The Prefer flag has no effect. Off: [default] No load balancing, read from preferred piece. To select the preferred disk, use menu action Prefer. Reject Info Reject DuplexWrite group information (via Plug and Play). Removing DuplexWrite group information only needed for maintenance in special cases. Fujitsu Technologie Solutions November 17, / 67

25 One case: If this cluster node blocks this resource due a fail over or move. Please use this function with care! Selectable only for DuplexWrite groups with status Cluster. Rename Change DuplexWrite group name. Status dependent actions: Add... Add second disk (piece) to selected DuplexWrite group. Dialog will display a list of all available disks. The selected one will be added as second piece to the DuplexWrite group. The disk size must be equal or greater than first piece's size. No user data will be affected. In MSCS installations shutdown the other node(s) first to avoid an inconsistent view of the storage resources. Selectable if the DuplexWrite group consists of one piece. The new disk status is Error. Start Recover to set the second piece online. The second piece will set immediately online if the first piece is empty. A disk is empty, if there is no any partition is available except the DuplexDataManager COD partition. Delete Group Delete selected DuplexWrite group: clear disk's COD partition/blocks. No user data will be affected. Use the SCSI view to administer non-ddm disks. In MSCS installations shutdown the other node(s) first to avoid an inconsistent view of the storage resources. Selectable if the DuplexWrite group consists of one piece. Resize Group Resize DuplexWrite group. If the DuplexWrite group was expanded, the new added space will be recovered automatically. The minimum DuplexWrite size is limited by the partitions available on the disk. If the COD position is at the end of the mirrored space, it will be moved on resizing. The minimum shrink/expand size is 39 MB (COD size). Windows Server 2008 and newer: Resize DuplexWrite Group is not supported if the Configuration On Disk (COD) partition is behind the system/data partition. By default only RootDisk mirrors are affected. All other cluster nodes MUST be rebooted after resizing. Selectable if all pieces are Online. Properties Help Show detailed information on selected DuplexWrite group. Open MMC's help facility. Fujitsu Technologie Solutions November 17, / 67

26 4.3 Node DuplexWrite Group Displays the associated DuplexWrite pieces. The DuplexWrite group name and optional the MultiPath group ID are shown. The result pane shows information on DuplexWrite group's disks. Status dependent icons Normal Open/Selected Disabled Error Recover CloneData Disk is Offline Disabled (hidden): A duplicate signature was detected on a disk. Action on DuplexWrite group node (right mouse button) Refresh Set Recover Mode... Refresh all MMC information. Recommended in case of failure situation to be sure that shown status is the current one. Mode to be used for recovery. Affects selected DuplexWrite group. Verify: [default] Read from both disks, compare and write if necessary (fast policy if disks are slightly different). Copy: Read from online disk and write to the second one (best policy if disks are completely different). Delta: Recover only delta areas since failure (fastest policy if disks are slightly different). Do not use Delta Recover when the disk to be recovered has been modified externally since failure (e.g. by another server or by exchanging one disk of a RAID group). Selectable only for Online DuplexWrite groups. Enable/Disable Diskload Balancing Set Dynamic Diskload Balancing On/Off. Affects selected DuplexWrite group. On: Both disks of the DuplexWrite group are used for read. A special load balancing algorithm determines best disk to read from. The Prefer flag has no effect. Off: [default] No load balancing, read from preferred disk. Fujitsu Technologie Solutions November 17, / 67

27 To select the preferred disk, use menu action Prefer. Reject Info Reject DuplexWrite group information (via Plug and Play). Removing DuplexWrite group information only needed for maintenance in special cases. One case: If this cluster node blocks this resource due a fail over or move. Please use this function with care! Selectable only for DuplexWrite groups with status Cluster. Rename Change DuplexWrite group name. Status dependent actions: Add... Add second disk (piece) to selected DuplexWrite group. A dialog will display a list of all available disks. The selected one will be added as second piece to the DuplexWrite group. The disk size must be equal or greater than first piece's size. No user data will be affected. In MSCS installations shutdown the other node(s) first to avoid an inconsistent view of the storage resources. Selectable if the DuplexWrite group consists of one disk. The new disk status is Error. Start Recover to set the second disk online. The second piece will set immediately online if the first piece is empty. A disk is empty, if there is no any partition is available except the DuplexDataManager COD partition. Delete Group Delete selected DuplexWrite group: clear disk's COD partition/blocks. No user data will be affected. Use the SCSI view to administer non-ddm disks. In MSCS installations shutdown the other node(s) first to avoid an inconsistent view to the storage resources. Selectable if the DuplexWrite group consists of one disk. Resize Group Resize DuplexWrite group. If the DuplexWrite group was expanded, the new added space will be recovered automatically. The minimum DuplexWrite size is limited by the partitions available on the disk. If the COD position is at the end of the mirrored space, it will be moved on resizing. The minimum shrink / expand size is 39 MB (COD size). Windows Server 2008 and newer: Resize DuplexWrite Group is not supported if the Configuration On Disk (COD) partition is behind the system/data partition. By default only RootDisk mirrors are affected. All other cluster nodes MUST be rebooted after resizing. Fujitsu Technologie Solutions November 17, / 67

28 Selectable if all pieces are Online. Properties Help Show detailed information on selected DuplexWrite group. Open MMC's help facility. Information on DuplexWrite piece(s) DWrite Status Disk's current DuplexWrite status. SCSI bus related information: Port Path Target LUN Disk MPath Group Unit Serial Number LUN WWN Port identifier. Sub-port identifier. Target identifier (SCSI-ID). Device Logical Unit (SCSI-LUN). Disk number (physical device number) as defined by operating system. Associated MultiPath group ID (if applicable). Unit Serial Number (if applicable). Logical Unit Number (LUN) World Wide Name (WWN). Only available for FibreCAT storage. Model / The storage model name and the connection type. e.g.: FibreCAT SX / iscsi. Connection Type Host Bus Adapter WWPN Controller/Port WWPN D_ID Displays the Host Bus Adapter World Wide Port Name (WWPN), if available. Displays the Controller/Port World Wide Port Name (WWPN), if available. Destination Identifier: An address contained in a Fibre Channel frame that identifies the destination of the frame. This ID displayed in the controller and system BIOS for a boot lun. The D_ID viewed also as Device Port ID (QLogic) and FC ID (Emulex). Action on selected DuplexWrite piece (right mouse button) Refresh Refresh all MMC information. Recommended in case of failure situation to be sure that shown status is the current one. Status dependent actions: Fujitsu Technologie Solutions November 17, / 67

29 Online Set selected disk (piece) online. The action depends on the state of the corresponding DuplexWrite group: The DuplexWrite group contains only one piece: Set the status of the selected piece to Online. The DuplexWrite group will be accessible to the application, subsequently. The DuplexWrite group consists of two pieces and the DuplexWrite status of both pieces is Error, or Disabled: Set the status of the selected piece to Online. The DuplexWrite group will be accessible to the application, subsequently. Be sure to select the most recently modified piece (flag Recent set). Open both pieces' Properties to get this information. Selectable if status is Disabled or Error. The new status is Online. Recover... Recover selected disk: Copy back all data from other piece. A dialog displays two options to start the process: Immediate: [default] Start process now. Timer: Select date and time when the process should start. You might get this error message: Start recover refused. This piece is the most resent one! See the online help for more information of this condition and search in the index for 'conserve' In this case the following has happened: The piece, which is in status error, is the more recent piece. Nevertheless it was set to error, because write commands were sent to the other piece, before the more recent piece appeared. If both pieces were switched now, the file system could be corrupted. Therefore the more recent piece stays in status Error. Because a recover would overwrite newer data, the recover is rejected in this case. There are two possibilities now: 1. The data on the more recent piece should be overwritten: Disable the error piece and start recover. 2. The data on the more recent piece should be conserved: If it is a system disk, the system has to be rebooted, while the first piece with older data must be disconnected. (disconnect LUN or change BIOS settings etc.) If it is a data disk, you can either reboot with disconnected older piece (see above) or follow these steps: Stop applications accessing this disk - remove drive letters - disable the online piece - set the error piece to online - start recover - reassign drive letters - start applications. Fujitsu Technologie Solutions November 17, / 67