User's Manual

hp StorageWorks File System Extender User Guide 175
The backup progress is recorded in the backup.log file. Once backup is finished, it reports barcodes of the
FSE backup media where backed up data is stored. Backup start and stop times are written to the
fse.log file and can help estimate the time needed for backup.
Backup media management
FSE backup requires special media management to ensure safety of the backed up data and to prevent
data loss.
NOTE: The FSE administrator is responsible for preparing and allocating backup media as well as for
keeping records on backup media, their usage and contents. These tasks are crucial for a successful
backup and restore of the FSE implementation.
Configuring a backup media pool
A separate media pool, called a backup media pool, must be configured before backing up the FSE
implementation. The backup media pool should be configured with only one volume in order to use all the
space on the medium. Backup media should not be initialized. The backup process rejects initialized
media in order to prevent overwriting FSE media by accident.
NOTE: Backup is done sequentially by one drive, therefore all backup media must belong to the inventory
of the same library.
Estimating resources
You must allocate enough media for a complete backup of the FSE implementation. If there is not enough
space on the requested media, backup fails. You can estimate the required capacity by calculating the
sizes of FSE implementation components involved in backup. Additionally, you can check the FSE backup
log for results on used media. Note that the FSE backup process always uses a complete medium; therefore
partially filled media from previous backups are not taken into account.
When the fsebackup command is run, it specifies a list of backup media it is going to use. The media
are used in the same sequence as specified at the command line.
Media recycling
New LTO Ultrium media have only one preformatted partition, and can be used for FSE backup
immediately, without the otherwise required formatting. However, if the media have already been used for
some purpose (FSE migrations or any other application), they may contain some data that will cause FSE to
refuse to overwrite them.
Preparing already used media for FSE backup purposes depends on media type.
CAUTION: Do not use the commands below while FSE is running. Ensure that the appropriate medium is
in the drive so it will not be accidentally reloaded by a migration or recall job. You can temporarily disable
a drive to ensure that the FSE jobs will not exchange the medium in the meantime. Do not use these
commands on media in active FSE pools since this can corrupt the whole system and cause unrecoverable
data loss.
• Reusing LTO Ultrium media for backup
To prepare used LTO Ultrium media for backup, you only need to clear the FSE header or any other
tape header; these headers prevent FSE from overwriting the tape. LTO Ultrium media are already
formatted to one partition. Proceed as follows:
Load the medium manually into the drive and clear the medium header using the fse_scsi tool. In
place of DeviceFile, specify the SCSI device ID of the drive:
fse_scsi DeviceFile --rew
fse_scsi DeviceFile --erase