User's Manual

hp StorageWorks File System Extender User Guide 171
7 Backup, restore, and recovery
FSE enables you to have several migrated copies of the same file data, thus ensuring availability of files in
case one of the copies is damaged. For details on configuring FSE to create multiple migrated copies, see
”Multiple copying” on page 131.
To make your FSE environment as safe and as stable as possible, you need to plan ahead and regularly
copy FSE databases and system files (FSE system data) onto different storage media. This copying process
is called FSE backup. Backup copies can be used to recreate original FSE data to a state equivalent to the
one at the time of backup. This process is called FSE restore.
Depending on the data that you have lost and the applicability of your backup copies, another process
can be used to recreate your data: FSE recovery. While FSE restore is the only way to recreate your data in
cases of an irreparably damaged server, FSE recovery is recommended if you need to recreate a particular
HSM file system or File System Catalog (FSC). The advantage of FSE recovery is that the process does not
depend on backup, and ensures that your FSE implementation is up-to-date with the actual state of FSE
media and/or FSC. You should consider it as an alternative to the backup and restore process in cases
where there are no existing up-to-date backup copies or where it is more efficient considering time and
complexity of the process.
The next sections provide recommendations on recreating your data, helpful hints on how to define your
backup strategy, and information on how to recover from actual data loss.
This chapter includes the following topics:
• Defining your backup strategy, page 171
• Backup, page 174
• Restore, page 182
• Recovery, page 186
Defining your backup strategy
Typically, if you make backup copies on a regular basis and according to recommendations (see ”Backup
media management” on page 175), you are able to restore any part of the FSE implementation (FSE
databases, FSE system files and user data). However, you should also consider using FSE recovery as a
method of recreating your data, and define your backup strategy accordingly.
FSE implementation components
The following table lists all FSE components that can be backed up. It states whether a component is FSE
client specific, and provides notes on possible methods of recreating your data.
FSE component Description Recovery method
HSM file system (client data) Needed to recover your files, file
system structure, file attributes, and
metadata. Offline files on the HSM
file system are backed up as sparse
files so they occupy negligible space
on the backup medium.
• Recover HSM FS (see ”HSM
file system recovery” on
page 186)
• Backup and restore (using full
backup or single client
backup)
Hierarchical Storage Management
Database (HSMDB) (client data)
Contains migration- and release
candidate lists for files on the HSM
file system. The restore of this
database recreates the state of
restored files; without it, the state of
files cannot be recreated during
restore, preventing files from being
migrated and released.
• If HSM FS is recovered,
special recovery of HSMDB is
not needed
• Backup and restore (using full
backup or single client
backup)