HP OpenView Storage Mirroring User Guide (360226-002, May 2004)

12 - 3
Restoration Options
When restoring Storage Mirroring data, you must specify the source and target machines and the replication set from the
source machine that contains the data that was lost and needs to be restored, as well as configure how the restoration process
will occur.
! Original Source—If you are restoring to a Storage Mirroring server other than where a replication set was created, you
must specify the original source machine.
! Restore From—You must specify the Storage Mirroring target machine where the copy of the data now resides and will
be restored from.
! Replication Set—You must specify the replication set that was originally defined to send the data from the source to the
target.
! Restore To—You must specify the Storage Mirroring machine where you want to restore the data. (In the Text Client,
this option is called original.)
! Use Backup Replication Set—You have the option of using the backup replication set database stored on the target for
the restoration or, if available, you can attempt to use the replication set from the source machine.
! Restore Replication Set—You have the option of restoring the target’s copy of the replication set to the source machine
during the restore process. This allows you to establish another connection after the restoration process without having
to re-create the replication set.
! Restore Conditionals—You have three restore conditionals that can be applied during the restoration process:
! Overwrite existing files during restore—With this option, the restoration process overwrites all existing files on
the source machine and restores those files that do not exist.
! Only if backup copy is more recent—With this option, the restoration process can be limited to only overwriting
the files that are newer on the target than on the source machine. Without this option, all files are overwritten
regardless of the file’s date and time stamps.
! Use block checksum comparison—With this option, the restoration process can be limited to only overwriting
blocks of data that are different on the source than on the target as determined by the block checksum comparisons.
With this option, only the blocks that are different are overwritten.
The following table illustrates how the restoration conditionals work together, as well as how they work with the global
checksum setting on the Source tab of the Server Properties. (Even though the target is doing the work, the settings on
the Server Properties Source tab do influence how the target transmits the data back to the source.) Determine which
options you need to select when configuring the restoration by identifying which type of action you want Storage
Mirroring to perform during the restoration process.
NOTE: If Use Backup Replication Set is selected during a restoration, Storage Mirroring attempts to use the
backup of the replication set database located on the target machine to identify the files to be restored.
The backup files are:
! source_machine_name.db
! source_machine_name.xfp
These files are located in the directory where Storage Mirroring is installed. If inconsistencies in the
network name-resolution exist, the name of the
.DB and .XFP files on the target may not be the name
Storage Mirroring expects. When these files are not found, the restore fails. Prior to a restore, verify that
the
.DB and .XFP files on the target machine match the source machine name.
NOTE: During a restoration, temporary connections are established between the source and target machines. Other
connections cannot be established between these two machines until the temporary connection is terminated.
This may take up to two minutes after a restoration is complete. Any connections attempted prior to the
temporary connection being terminated will fail. Any connections attempted after the temporary connection
is terminated, will function properly.
When a file is restored, the global unique ID (GUID) used in Windows 200x is also restored from the target’s
attribute database.