The following steps must be completed before performing a restoration:
Dismount the storage group
Stop resource monitoring for the physical disk
Stop the QuickOPC session (only for differential snapshot type backups)
Use the Exchange management console and set the "Overwrite this database when restoring" option for all stores in the target storage group.
Use the Exchange system manager or Exchange management console and dismount all of the stores in the storage group that is to be restored. After dismounting the stores, close the Exchange system manager or the Exchange management console.
When the Exchange Server is using WSFC operation, LUN unit copying is used when a WSFC shared volume is restored. Therefore, resource monitoring must be stopped.
Note
The disks for which resource monitoring is to be stopped differ according to the restoration method. Refer to "9.1.5.2 Executing the restoration" for more information.
For "Point-in-Time" restorations, all physical disk resources where storage groups (files with extensions *.edb, *.log and *.chk) are located must be stopped.
For roll-forward restorations, only physical disk resources where database files (files with extension *.edb) are located must be stopped. In this case, no problems will occur if resource monitoring is stopped for all physical disk resources where storage groups are located.
Stop resource monitoring by switching the resources to maintenance mode by using the cluster command.
[Example (Switching physical disk resource "Disk J:" to maintenance mode)]
C:\>cluster ExampleCluster res "Disk J:" /maint:on Setting maintenance mode for resource 'Disk J:' Resource Group Node Status -------------------- -------------------- --------------- ------ Disk J: GRP1 NODE1 Online(Maintenance) C:\> |
For differential snapshot type backups, all of the QuickOPCs that have been set up on the transaction disk must be canceled using swsrpshadowadm_exchange (Exchange VSS shadow copy management command) before the restoration is executed. swsrpshadowadm_exchange (Exchange VSS shadow copy management command)can be used to check the QuickOPC sessions that have been set up on the transaction disk.
Note
Restoration cannot be executed if there are any backup disks on the transaction disk that are undergoing QuickOPC.
In order to cancel QuickOPC where physical copies are in progress, the shadow copies must be deleted first.
Restoration is performed separately for each storage group, using swsrpvssrestore_exchange (Exchange VSS restoration execution command) on the Exchange server. When this command is executed, all of the databases (i.e. stores) in the storage group are dismounted. Restoration is performed using AdvancedCopy (OPC).
There are two restoration methods:
Point-in-time restoration (restoring to the point when the (last) backup was taken)
Roll-forward restoration (restoring to the latest point)
Point-in-time restoration works by restoring all of the databases in the storage group to the state they were in when the backup was taken. Point-in-time restorations are executed by specifying the "point" option with swsrpvssrestore_exchange (Exchange VSS restoration execution command). If the "point" option is specified, this command will restore the storage group to the point when the backup was taken by restoring all of the files (files with extensions *.edb, *.log and *.chk) that make up the storage group.
Figure 9.49 Point-in-time restoration
Example:
C:\>set SWSTGNODE=nodeAGT C:\>C:\Win32App\AdvancedCopyManager\bin\swsrpvssrestore_exchange -evs VSVR -point -sgname FirstStorageGroup swsrpvssrestore_exchange successfully completed C:\> |
Roll forward restorations restore all of the databases in the storage group to the latest point.
Roll forward restorations are executed by specifying the "roll" option with swsrpvssrestore_exchange (Exchange VSS restoration execution command). If the "roll" option is specified, the restore is performed as follows:
Only database files (with extension *.edb) are restored.
Logs are applied using the log files that exist on the transaction volume.
Databases are restored to the latest point.
Figure 9.50 Roll forward restoration
Example:
C:\>set SWSTGNODE=nodeAGT C:\>C:\Win32App\AdvancedCopyManager\bin\swsrpvssrestore_exchange -evs VSVR -roll -sgname FirstStorageGroup swsrpvssrestore_exchange successfully completed C:\> |
Note
In order to execute a roll forward restoration, the following conditions must be met:
All of the transaction logs that have been created since the latest complete backup was taken must exist.
The generation numbers (the "XXXXX" part of EOnXXXXX.log) of the existing log files must be consecutive.
A new backup must be created immediately if the database path is changed.
A new backup must be created immediately after the commands ESEUTIL /p (restores faults or damaged databases) or ESEUTIL /d (defrags or compresses databases) are executed.
A backup of all databases in the storage group must be taken immediately after any databases are added or deleted.
swsrpstat_exchange (Exchange operation status display command) can be used to check the restoration copy implementation status.
[Execution example (when OPC used to perform restoration)]
C:\> C:\Win32App\AdvancedCopyManager\bin\swsrpstat_exchange -sgname FirstStorageGroup Server Original-Volume Replica-Volume Direction Status Execute EXCHG-SVR g1d1p1@EXCHG-SVR g1d11p1@BKUP-SVR reverse snap 80% EXCHG-SVR g1d2p1@EXCHG-SVR g1d12p1@BKUP-SVR reverse snap 63% EXCHG-SVR g1d1p1@EXCHG-SVR g1d13p1@BKUP-SVR ---- ---- ---- EXCHG-SVR g1d2p1@EXCHG-SVR g1d14p1@BKUP-SVR ---- ---- ---- C:\> |
The following steps must be completed after performing a restoration:
Restart resource monitoring for physical disks.
Mount the storage group.
Restart resource monitoring by canceling maintenance mode for the physical disks where resource monitoring has been stopped.
[Example (Releasing physical disk resource "Disk J:" from maintenance mode)]
C:\>cluster ExampleCluster res "Disk J:" /maint:off Clearing maintenance mode for resource 'Disk J:' Resource Group Node Status -------------------- -------------------- --------------- ------ Disk J: GRP1 NODE1 Online C:\> |
For point-in-time restore, use the Exchange system manager to mount all stores that have been dismounted. Use the following procedure to mount the stores for roll forward restorations:
For roll forward restorations, either delete or rename the CHK file (EXX.chk). (For Point-in-Time restorations, do not perform this procedure.)
Use the Exchange management console to mount all the stores that have been dismounted.
When data backed up to tape is to be restored, the backup data on the tape first needs to be restored on the backup server and then the Exchange VSS restore command needs to be entered.
If the backup volume is used as a shadow copy, the backup data on the tape must be restored after deleting the shadow copy. The figure below shows the flow of a restoration from tape.
Figure 9.51 Snapshot restoration (restoration performed using OPC)
