HP OpenView Storage Data Protector A.05.10 ZDB for HP StorageWorks Enterprise Virtual Array (EVA) in the CA Configuration White Paper Edition: August 2004 Manufacturing Part Number: n/a August 2004 Copyright Hewlett-Packard Development Company, L.P.2004.
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Chapter 1: Introduction... 5 1.1 In This White Paper...5 1.2 Before Reading On...5 1.3 Terminology Conventions...6 Chapter 2: Overview... 7 2.1 ZDB Tape Backup on CA EVA...7 2.2 Upgrade Considerations...7 Chapter 3: Concepts... 9 3.1 Prerequisites...9 3.2 Limitations...9 3.3 CA EVA-Related Definitions...9 3.4 High Availability and Data Safety in CA EVA...10 3.4.1 Data Replication and Failover... 10 3.4.2 CA EVA Logs... 10 3.4.3 Data Replication Group States... 11 3.5 Snapshot Backup on the CA EVA...11 3.6 Layout of a Data Protector Cell Using the CA EVA Configuration...11 3.7 Performance Influences and Implications...13 3.7.1 ZDB Tape Backup of the Source Virtual Disks... 13 3.7.2 ZDB Tape Backup of the Destination Virtual Disks... 13 3.7.3 Restore to the Source Virtual Disks... 13 3.7.4 Restore to the Destination Virtual Disks... 13 Chapter 4: Performing a Snapshot Backup on CA EVA... 15 4.1 Configuring a CA EVA Backup Specification...15 4.2 Starting or Scheduling a CA EVA Snapshot Backup...17 Chapter 5: EVA and CA EVA-Specific Backup Options... 19 5.1 EVA Backup Options...19 5.1.1 EVA Replica Storage Management Options... 19 5.1.2 EVA Snapshot Management Options... 21 5.1.3 EVA Mount Options... 23 5.2 CA EVA Backup Options...24 3
5.2.1 EVA and Continuous Access Configuration Option... 24 5.2.2 EVA in Continuous Access Configuration Specific Options... 24 Chapter 6: Restoring Data on CA EVA... 27 6.1 Restoring to the Source Virtual Disks...27 6.1.1 Restore Procedure... 27 6.2 Restoring to the Destination Virtual Disks...27 Chapter 7: New omnirc Variables... 29 7.1 Variables for Fine-Tuning the EVA Agent Operation with CA EVA...29 Chapter 8: Troubleshooting... 31 4
Chapter 1: Introduction 1.1 In This White Paper This white paper describes the extension of HP OpenView Storage Data Protector A.05.10 which enables you to perform zero downtime backup using HP StorageWorks Continuous Access EVA. The purpose of the white paper is to provide you with the following: Description of the backup functionality provided by this Data Protector extension. See Chapter 2, Overview, on page 7. Overview of the Continuous Access EVA concepts, CA EVA operation, and its integration with the Data Protector cell. See Chapter 3, Concepts, on page 9. Procedure for configuring a ZDB tape backup specification for CA EVA using the Data Protector GUI. See Chapter 4, Performing a Snapshot Backup on CA EVA, on page 15. Description of the EVA and CA EVA-specific backup options that can be specified while configuring a CA EVA backup specification in the Data Protector GUI. See Chapter 5, EVA and CA EVA-Specific Backup Options, on page 19. Procedure for restoring the data on CA EVA. See Chapter 6, Restoring Data on CA EVA, on page 27. New omnirc variables that are used for fine tuning the operation of the EVA agent on CA EVA. See Chapter 7, New omnirc Variables, on page 29. The target audience of this document are backup administrators who integrate Continuous Access EVA with the Data Protector cell, and backup operators who use such a backup environment for zero downtime backup (ZDB) and restore processes. 1.2 Before Reading On There are a few prerequisites that you have to fulfil before reading this document: You should have access to the complete set of the HP OpenView Storage Data Protector A.05.10 manuals in either printed or electronic format. You should be familiar with basic concepts of the zero downtime backup (ZDB) functionality. For information on the ZDB concepts, refer to the HP OpenView Storage Data Protector EVA/VA/MSA Integration Guide, chapter 1 Overview. It is advised that you have some experience in performing basic ZDB tasks. For information on the ZDB task procedures, refer to the HP OpenView Storage Data Protector EVA/VA/MSA Integration Guide. 5
1.3 Terminology Conventions Throughout the document, in order to make the text clearer and more readable, the following terminology conventions are used. Term Data Protector EVA CA EVA Meaning Data Protector A.05.10 HP StorageWorks Enterprise Virtual Array HP StorageWorks Continuous Access EVA CA EVA are two identical interconnected EVAs that communicate bidirectionally in order to provide high availability and disaster-tolerance of the stored data. EVA+BC an EVA installed with HP StorageWorks Business Copy EVA HP StorageWorks Business Copy EVA is a software module that enables creation of snapshots (standard snapshots, virtual snapshots or snapclones) on EVA. It is a prerequisite for performing zero downtime backup on EVA. EVA+BC is described and referred to as EVA in the HP OpenView Storage Data Protector EVA/VA/MSA Integration Guide for Data Protector A.05.10. ZDB IR ZDB for CA EVA extension zero downtime backup instant recovery A Data Protector A.05.10 patch that enables ZDB of the destination virtual disks on CA EVA on the Windows Server 2003 platform. 6
Chapter 2: Overview Until now, Data Protector enabled ZDB to be performed only on EVA+BC. On such an EVA, you can choose to perform any of the three snapshot backup session types: ZDB disk backup, ZDB disk/tape backup, and ZDB tape backup. If you back up the data using either of the first two backup session types, you can later restore it using instant recovery (IR). 2.1 ZDB Tape Backup on CA EVA When Data Protector is upgraded with the ZDB for CA EVA extension, ZDB functionality is also enabled for the destination virtual disks on CA EVA. However, on such an EVA configuration IR is not possible, and - consequently - only ZDB tape backup sessions can be performed. The data backed up in ZDB tape backup session can be restored using the standard Data Protector restore procedure. Nevertheless, the ZDB for CA EVA extension enables you to configure the ZDB tape backup specification in such a way that after the backup to tape media, the replica is kept on the EVA disk array for purposes other than IR. The ZDB for CA EVA extension was designed to meet the requirements of the following Data Protector customer groups: The customers who are using the CA EVA high availability solution with one of the EVA disk arrays not fully loaded. This EVA disk array can be utilized to create snapshots and back up data to the tape device. During the ZDB process, the performance of the other EVA disk array is not affected. The customers who are using the CA EVA high availability solution, and who want to have backups present on both locations. This extra backup policy increases the safety of the backed up data. For conceptual overview of the CA EVA operation in a Data Protector backup environment and the physical layout of the EVA disk arrays in the Data Protector cell, see Chapter 3, Concepts, on page 9. For more information on EVA disk arrays, refer to the Virtual array systems section of the web page http://h18004.www1.hp.com/storage/arraysystems.html. 2.2 Upgrade Considerations Note that after upgrading your EVA+BC high-availability environment to CA EVA, and upgrading Data Protector with the ZDB for CA EVA extension, IR will only be enabled for those virtual disks that are not part of a copy set (are configured as a local storage only). This means that for the virtual disks that are part of a copy set: The data that was backed up on EVA+BC in a ZDB disk backup session cannot be restored, as IR is the only method that can be used for restoring such data. The data that was backed up on EVA+BC in a ZDB disk/tape backup session can be restored only from tape media. The data that was backed up on EVA+BC in a ZDB tape backup session can be restored as usual. The above IR limitation is imposed by the CA EVA configuration, and not by the ZDB for CA EVA extension. 7
Chapter 3: Concepts 3.1 Prerequisites To be able to perform a ZDB session on CA EVA, the following prerequisites have to be fulfilled: You must have the EVA Business Copy and Continuous Access licenses. For information on how to obtain these licenses, refer to the CA EVA documentation. A VCS firmware version prior to 3.020 must be installed in the CA EVA HSV controllers. A Command View EVA software version prior to 3.2 must be installed on each Storage Management Appliance (SMA). SMA is a specialized server on which SAN applications and Command View EVA software run. HP StorageWorks Continuous Access EVA 1.1A management software must be installed on the system from which the CA EVA will be managed. 3.2 Limitations Usage of the ZDB for CA EVA extension on CA EVA is bound by the following limitation: Only filesystem and disk image (rawdisk) backups are supported. The application and backup systems must host the Windows Server 2003 operating system. 3.3 CA EVA-Related Definitions The definitions of the terms specific to CA EVA are listed in the table below. Term primary or local site Definition one or more EVA disk arrays residing at the local data storage center, which contain(s) the original data A storage system may be considered local (primary) site for some virtual disks, and remote (secondary) site for other virtual disks. secondary or remote site one or more EVA disk arrays that contain(s) copies of the original data A remote site may be located in the same room or building as the local site. In most cases, however, it is located in a more distant place. copy set a pair of virtual disks, one located on the local EVA disk array and the other on the remote EVA disk array, which are mirrored Mirroring means replicating the data located on a source virtual disk on the local site to a destination virtual disk on the remote site. 9
Term data replication group (DR group) source virtual disk destination virtual disk failover DR group failover Definition a grouping of up to eight copy sets that have common characteristics and share a common CA EVA log a virtual disk that contains original data which is replicated to a destination virtual disk a virtual disk that is the recipient of replicated data from a source virtual disk. In general, the meaning of this term is context-specific. In this white paper, failover is only used to denote DR group failover. an operation that reverses the direction of data replication in a DR group For definition of other technical terms related to EVA and CA EVA, refer to the CA EVA documentation, and to the Command View EVA online help. 3.4 High Availability and Data Safety in CA EVA 3.4.1 Data Replication and Failover On CA EVA, the DR groups are configured in such a way that your data located on the source virtual disks on the local disk array (visible from the application system) is constantly replicated to the destination virtual disks on the remote disk array. If a disaster of the source virtual disks (with original data) occurs, an unplanned failover is automatically triggered by the EVA controllers. During the failover, the destination virtual disks of the "failed over" DR groups on the remote disk array take the role of the corresponding source virtual disks of the same DR groups on the local disk array, and the direction of data replication reverses. After the failover, in order for you resume with normal operation on the application system, you should establish a connection between this system and the remote disk array, and restart the system. After the original data is recovered, a planned failover (induced by the user) reverts the data replication direction to the initially configured direction. 3.4.2 CA EVA Logs The disk array containing the source virtual disks has some storage space dedicated for logging purposes. In circumstances where data replication in CA EVA is not possible, due to broken connection between the source and destination disks, or some other reason, new data and changes to the existing data on the application system are logged to the log space on the local disk array. Each DR group configured on the disk array has its own log. During the logging process, the status of the DR groups with the source virtual disks being replicated is set to "logging". After the connection between the disk arrays is reestablished, the contents of the log are merged with the contents of the corresponding destination virtual disks on the remote disk array, so that the redundancy of data is restored. For the duration of this activity, the status of the involved DR groups is set to "merging". After merging is complete, the status is set back to "normal". If the interruption of data replication in CA EVA is long-lasting, the free storage space reserved for the DR group logs on the local disk array may run out. In this case the logs cannot hold all the changes to the original data. After the connection between the disk arrays is reestablished, all original data in the involved DR groups has to be copied over. During copying, the status of the DR groups with the source virtual disks being replicated is set to "copying", and reset to "normal" after the operation is complete. 10
3.4.3 Data Replication Group States Each DR group in CA EVA can be in one of the following states: "normal", "error", "warning", "unknown". Only when a DR group is in the "normal" or "warning" state, the data on the destination virtual disks is always consistent with the data on the destination virtual disks (of the same copy sets). Other states do not guarantee this consistency. The "suspend" mode of a DR group indicates that data replication of the belonging source virtual disks is suspended. Changes to the existing data located on these virtual disks are logged to the CA EVA log until data replication is resumed. In the "suspend" mode, the state of the DR group is set to "logging". 3.5 Snapshot Backup on the CA EVA During snapshot backup on an EVA+BC, a replica of the virtual disks is created on the EVA disk array first and then backed up to the tape media. On CA EVA, the ZDB for CA EVA extension enables two variants of ZDB to be performed with Data Protector: The destination virtual disks of the copy sets (DR groups) are backed up (the replica is created on the remote disk array). The source virtual disks of the copy sets (DR groups) are backed up (the replica is created on the local disk array). In either case, the backup system must have access to the virtual disks being backed up. The tape device can be located on an arbitrary place, as long as it is visible from the backup system. By default, running the first ZDB variant, that is, backup of the destination virtual disks, succeeds only if the involved DR groups are in the "normal" or "warning" state, as in these cases the consistency of the backed up data is guaranteed. However, there are situations, when you are willing to sacrifice data consistency in favour of performing a ZDB session for the destination virtual disks. For such occasions, you can specify additional ZDB options that enable ZDB sessions even when the involved DR groups are in the "error" or "warning" state. Note that in the latter cases, the consistency of the backed up data is not guaranteed. 3.6 Layout of a Data Protector Cell Using the CA EVA Configuration In a Data Protector cell where ZDB sessions are performed using the CA EVA, three systems in the cell have special roles: Cell Manager, application system, and backup system. Cell Manager has a standard role in the cell, and can host Windows Server 2003 or any other operating system that supports the Data Protector ZDB functionality. Application system is a Data Protector client that uses the source virtual disks of CA EVA for data storage. Backup system is a Data Protector client that must have access to the source virtual disks (if backup of the source virtual disks will be performed) or the destination virtual disks (if backup of the destination virtual disks will be performed). The three roles can be physically implemented with one, two, or three hosts. However, having the application system and backup system implemented with two different hosts has the following advantages: The performance of the applications running on the application system does not degrade during backup from the replica on the remote disk array to tape media. If the EVA disk arrays are located on sites on different physical locations, and backup of the destination virtual disks is performed, during the ZDB session the SAN between the sites will not increase, provided the network is configured properly. 11
Cell Configuration for Backing Up Data by Replicating the Source Virtual Disks Cell Configuration for Backing Up Data by Replicating the Destination Virtual Disks In order to be able to restore data from the tape device to the source virtual disks, the application system should have access to the tape device from which the data will be restored. 12
3.7 Performance Influences and Implications 3.7.1 ZDB Tape Backup of the Source Virtual Disks The performance of ZDB tape backup of the source virtual disks is limited by the network throughput between the local disk array and the tape device. As the tape device is connected to the backup system, including this system and the device into same network on the primary site is convenient for backup of the source virtual disks. In this case, for a properly configured CA EVA, the data stream will be localized to the primary site and will not load the SAN between the two EVA disk arrays, as long as the backup system is not part of the same SAN. During creation of the replica on the local disk array, the performance of the local disk array degrades. Thus, for the time of the replica creation, the applications running on the application system are affected. You are recommended to use this variant of the ZDB tape backup only if the backup media location does matter, or you want to have the backup media present on both sites, local and remote. 3.7.2 ZDB Tape Backup of the Destination Virtual Disks The performance of ZDB tape backup of the destination virtual disks is limited by the network throughput between the remote disk array and the tape device. Analogously, including the backup system and the tape device into the same network on the secondary site is convenient for backup of the destination virtual disks. In this case, for a properly configured CA EVA, the data stream will be localized to the secondary site and will not load the SAN between the two EVA disk arrays, as long as the backup system is not part of the same SAN. During creation of the replica on the remote disk array, the performance of the local disk array does not degrade. Thus, for the time of the replica creation, the applications running on the application system are not affected. If the location of the backup media does not matter, this variant of the ZDB tape backup is performance wise better than the ZDB tape backup of the source virtual disks. 3.7.3 Restore to the Source Virtual Disks The restore performance is limited by the connection speed between the tape device from which the data is restored and the source disk array. 3.7.4 Restore to the Destination Virtual Disks Restore to the destination virtual disks is not possible because these disks cannot be mounted. 13
Chapter 4: Performing a Snapshot Backup on CA EVA Use the Data Protector GUI to create a filesystem or disk image ZDB backup specification for a backup session that will run on CA EVA configuration. After the backup specification is configured and saved, a zero downtime backup can be started using the Data Protector GUI or scheduled using the Data Protector scheduler. 4.1 Configuring a CA EVA Backup Specification Configuring a ZDB backup specification for CA EVA is similar to configuring a backup specification for EVA+BC. In both cases, the same configuration procedure is used. With CA EVA, however, some of the EVA options do not apply, and there are a few additional steps which you have to perform. When configuring a CA EVA backup specification, some of the common EVA backup options have a different meaning when used for CA EVA backup, and some additional CA EVA-specific options are available. For detailed information on these options, see EVA Backup Options on page 19 and CA EVA Backup Options on page 24, respectively. For information of other common ZDB options for EVA, refer to the HP OpenView Storage Data Protector EVA/VA/MSA Integration Guide. Figure 1 - General EVA Backup Options Available For ZDB on CA EVA 15
The procedure for configuring an EVA backup specification is described in the HP OpenView Storage Data Protector EVA/VA/MSA Integration Guide, chapter 3 Snapshot Backup, section Configuring an EVA Backup Specification. To configure a CA EVA ZDB backup specification, proceed as follows: 1. Perform the steps 1 and 2 of the referred procedure. 2. Specify the EVA-specific backup options: a. Under Client systems, select the application and backup systems in the Application system and the Backup system drop-down lists. Note that the application system must have access to the source virtual disks. The backup system must have access to the replica of the source virtual disks (if backup of the source virtual disks will be performed) or the replica of the destination virtual disks (if backup of the destination virtual disks will be performed), and have the tape device connected. b. In the EVA and Continuous Access configuration group box, select the All disks to be backed up are part of CA configuration option. Click Specifics. In the EVA in Continuous Access configuration specific options window, specify the options specific to ZDB tape backup on CA EVA. See figures 2 and 3. For detailed information on these options, see EVA in Continuous Access Configuration Specific Options on page 24. Click OK. Figure 2 - CA EVA-Specific Backup Options Selected for Backup of the Source Virtual Disks 16
Figure 3 - CA EVA-Specific ZDB Options Available for Backup of the Destination Virtual Disks c. Select other EVA backup options. For details, see Chapter 5, EVA and CA EVA-Specific Backup Options, on page 19. 3. Perform the steps 4 to 9 of the referred procedure. 4.2 Starting or Scheduling a CA EVA Snapshot Backup Use standard procedures for starting or scheduling a CA EVA ZDB session. For details on these procedures, refer to the HP OpenView Storage Data Protector EVA/VA/MSA Integration Guide, chapter 3 Snapshot Backup, section Running and Scheduling Snapshot Backup. 17
Chapter 5: EVA and CA EVA-Specific Backup Options 5.1 EVA Backup Options The following tables list common EVA backup options with the descriptions that apply when used for configuring a ZDB specification for CA EVA. 5.1.1 EVA Replica Storage Management Options Keep the replica storage after the backup Select this option to keep the replica storage version on a disk array after the ZDB tape backup session is completed. By selecting this option, the replica storage version becomes part of a replica storage pool; therefore, you should also set the Number of replica storages rotated parameter (see below). If this option is not selected, the replica storage version is deleted after the ZDB tape backup session is completed. By default, this option is selected. 19
Number of replica storages rotated Specify the number of replica storage versions you want to keep on a disk array. During every backup session, Data Protector creates a new replica storage version and leaves it on the local disk array (in case of the source virtual disks backup) or on the remote disk array (in case of the destination virtual disks backup) as long as the specified number is not reached. When the specified number is reached, Data Protector deletes the oldest replica storage version on the local disk array (in case of the source virtual disks backup) or on the remote disk array (in case of the destination virtual disks backup) and creates a new one. Note that this option sets the number of replica storage versions in the replica storage pool that belongs to the backup specification you are configuring. The replica storage pool will be created (or reused, if it already exists) on the disk array with the virtual disks that are selected for backup. If a failover occurs before the corresponding ZDB session is started, the replica storage pool will be created (or reused, if it already exists) on the other disk array. Thus, this option limits the number of replica storage versions on each disk array. You need to specify this number if the Keep the replica storage after the backup option is selected. By default, this number is set to 1. Note that the maximum number for vsnaps and standard snapshots is 7. Data Protector does not limit the number of replica storage versions rotated, but the session will fail if the limit is exceeded. 20
5.1.2 EVA Snapshot Management Options Vsnap Select this option to create snapshots of the source virtual disks (in case of the source virtual disks backup) or the destination virtual disks (in case of the destination virtual disks backup) without the pre-allocation of disk space. For more information on this type of snapshot, refer to the HP OpenView Storage Data Protector EVA/VA/MSA Integration Guide, chapter 1 Overview, section Concepts, subsection Snapshot Types. This is the default selection. Standard snapshot Select this option to create snapshots of the source virtual disks (in case of the source virtual disks backup) or the destination virtual disks (in case of the destination virtual disks backup) with the pre-allocation of disk space. For more information on this type of snapshot, refer to the HP OpenView Storage Data Protector EVA/VA/MSA Integration Guide, chapter 1 Overview, section Concepts, subsection Snapshot Types. Snapshot type Snapclone Select this option to create clones of the source virtual disks (in case of the source virtual disks backup) or the destination virtual disks (in case of the destination virtual disks backup). For more information on this type of snapshot, refer to the HP OpenView Storage Data Protector EVA/VA/MSA Integration Guide, chapter 1 Overview, section Concepts, subsection Snapshot Types. 21
Strict With this option selected, Data Protector attempts to create snapshots of the type selected by the Snapshot type option. If some of the existing snapshots in the corresponding replica storage pool are of a different type, the selected type of snapshots cannot be used. Such a backup session will be aborted. This is the default selection. Loose With this option selected, Data Protector creates snapshots of a different type than specified by the Snapshot type option when this would help to make a successful session. For example, if you select standard snapshots to be created, but Data Protector detects that standard snapshots cannot be created because some vsnaps or snapclones of the source virtual disks (in case of the source virtual disks backup) or the destination virtual disks (in case of the destination virtual disks backup) already exist in the replica storage pool, the following happens: with the Loose option selected, Data Protector creates either vsnaps (if vsnaps already exist) or snapclones (if snapclones already exist) instead of standard snapshots. Snapshot policy Note that Data Protector can use only one type of snapshots in a backup session. For example, if some of the source virtual disks (in case of the source virtual disks backup) or the destination virtual disks (in case of the destination virtual disks backup) used in the backup session have existing standard snapshots and some of them existing vsnaps, the backup session will be aborted. Delay the tape backup by a maximum of X minutes if the snapclones are not fully created You can select this option if the selected snapshot type is Snapclone. Select this option if you want to delay moving data to tape media until the cloning process is completed. Specify also the maximum waiting time in minutes. After the specified number of minutes, the backup to tape will start, even if the cloning process is not finished yet. With this option, you actually achieve that during the backup data is read from the replica rather than the source virtual disks (in case of the source virtual disks backup) or the destination virtual disks (in case of the destination virtual disks backup). Thus, you prevent degradation of the application data access times during the phase of backup to tape. 22
5.1.3 EVA Mount Options Dismount the filesystems on the application system Select this option if you want the filesystem on the application system to be dismounted before a snapshot is created and remounted after a snapshot is created. A filesystem does not have the stop I/O functionality to flush the data from the filesystem cache to the disk and stop the I/O for the time of the snapshot. This option can be used to ensure that the data on the filesystem is consistent. By default, this option is not selected. Enable the backup system in read/write mode This option is related to UNIX systems only, since on Windows systems filesystems are always mounted in read/write mode. As CA EVA backup runs on Windows Server 2003 systems only, this option is ignored. 23
5.2 CA EVA Backup Options The following tables describe the EVA backup options that you can specify when configuring a ZDB backup specification for CA EVA. 5.2.1 EVA and Continuous Access Configuration Option If you are modifying a ZDB backup specification, the following option is available in the HP StorageWorks EVA property page of the Backup Options window. All vdisks to be backed up are part of CA configuration Select this option to configure a ZDB backup specification for CA EVA. If this option is not available, then either of the systems specified in the Client systems group box is not a Windows Server 2003 system. A ZDB session on CA EVA cannot be performed in such a backup environment. By default, this option is not selected. 5.2.2 EVA in Continuous Access Configuration Specific Options The following options are available only if the All vdisks to be backed up are part of CA configuration option is selected. Location options backup of the Source vdisks backup of the Destination vdisks Select this option to configure a filesystem or disk image backup of the data stored on the local disk array, that is, by replicating the source virtual disks. This is the default selection. Select this option to configure a filesystem or disk image backup of the data stored on the remote disk array, that is, by replicating the destination virtual disks. 24
Advanced options This set of options is only available if the backup of the Destination vdisks option is selected. Force backup when Log state is "Logging" Force backup when Log state is "Merging" Force backup when Log state is "Copying" Force backup when Disk replication group state is "Error" Force backup when Disk replication group state is "Unknown" Force backup when Disk replication group is in suspend mode Select this option to perform snapshot backup when the DR group that contains the virtual disk being replicated is in the "logging" state. Note that in this case, integrity of the backed up data is not guaranteed. For more information on the CA EVA log states, see CA EVA Logs on page 10. Select this option to perform snapshot backup when the DR group that contains the virtual disk being replicated is in the "merging" state. Note that in this case, integrity of the backed up data is not guaranteed. For more information on the CA EVA log states, see CA EVA Logs on page 10. Select this option to perform snapshot backup when the DR group that contains the virtual disk being replicated is in the "copying" state. Note that in this case, integrity of the backed up data is not guaranteed. For more information on the CA EVA log states, see CA EVA Logs on page 10. Select this option to perform snapshot backup when the DR group that contains the virtual disk being replicated is in the "error" state. For more information on the CA EVA log states, see CA EVA Logs on page 10. Select this option to perform snapshot backup when the DR group that contains the virtual disk being replicated is in the "unknown" state. For more information on the CA EVA disk replication group states, see Data Replication Group States on page 11. Select this option to perform snapshot backup when the DR group that contains the virtual disk being replicated is in the "suspend" mode. Note that in this mode, the state of the DR group is set to "logging", and the integrity of the backed up data is not guaranteed. For more information on the CA EVA data replication group states, see Data Replication Group States on page 11. This option is only available if the backup of the Destination vdisks option is selected. 25
Chapter 6: Restoring Data on CA EVA The data backed up in a CA EVA backup session can be restored to the application system s virtual disks using the standard restore procedure. 6.1 Restoring to the Source Virtual Disks During restore, the backed up data is restored from the tape device to the source virtual disks, which reside on the local disk array. In a backup environment with CA EVA, this is the ordinary type of restore that is expected to be used in most cases. For performance-related considerations, see section Performance Influences and Implications on page 13. 6.1.1 Restore Procedure Depending on the type of data that was backed up (filesystem data or disk image data), the procedure for this type of restore is the same as standard Data Protector filesystem or disk image restore procedure. For details, refer to HP OpenView Storage Data Protector EVA/VA/MSA Integration Guide, chapter 3 Snapshot Restore, section Restoring from Backup Media on LAN. 6.2 Restoring to the Destination Virtual Disks This advanced procedure includes restarting the application system, dismounting the source virtual disks, and performing a planned failover. The process is not supported by the ZDB for CA EVA extension and has to be performed manually. 27
Chapter 7: New omnirc Variables The ZDB for CA EVA extension introduces support for new environment variables that can be set in the <Data_Protector_home>\omnirc file on both the application and backup systems. You can use these variables to customize the operation of the Data Protector EVA agent in the CA EVA backup environment. Refer to the HP OpenView Storage Data Protector Administrator s Guide for information on how to use the omnirc file. 7.1 Variables for Fine-Tuning the EVA Agent Operation with CA EVA Four additional omnirc variables were defined for handling the time-outs when waiting for the destination virtual disks to become up-to-date or when the copy set appeared to be in a non-normal state. EVACA_QUERY_INTERVAL: This variable specifies the time interval (in minutes) between queries of the EVA storage system for checking the progress of the logging and/or copying process in CA EVA. Such querying takes place during a ZDB tape backup session immediately after the resolving phase of the backup system is complete. The default value of this variable is 5 minutes. EVACA_MSGWAITING_INTERVAL: This variable specifies the time interval (in minutes) between messages that report the progress of the logging and/or copying process in CA EVA. The progress is monitored during a ZDB tape backup session immediately after the resolving phase of the backup system is complete. The default value of this variable is 10 minutes. EVACA_COPYSTATE_TIMEOUT: This variable specifies the time interval (in minutes) after which the backup process will stop waiting for the DR group that has been found in the "copying" state. The snapshot backup process will skip the source virtual disks (in case of the source virtual disks backup) or the destination virtual disks (in case of the destination virtual disks backup) that belong to the DR groups which are in the "copying" state, and continue creating replicas of other virtual disks that might be part of the ZDB backup specification. The default value of this variable is 15 minutes. EVACA_MERGINGSTATE_TIMEOUT: This variable specifies the time interval (in minutes) after which the backup process will stop waiting for the DR group that has been found in the "merging" state. The snapshot backup process will skip the source virtual disks (in case of the source virtual disks backup) or the destination virtual disks (in case of the destination virtual disks backup) that belong to the DR groups which are in the "merging" state, and continue creating replicas of other virtual disks that might be part of the ZDB backup specification. The default value of this variable is 15 minutes. For information on other EVA agent-related environment variables, refer to the HP OpenView Storage Data Protector EVA/VA/MSA Integration Guide. 29
Chapter 8: Troubleshooting For general troubleshooting of ZDB tape backup and restore sessions on EVA, refer to the Troubleshooting sections in the HP OpenView Storage Data Protector EVA/VA/MSA Integration Guide, in chapters 3 Snapshot Backup and 4 Snapshot Restore. 31