User's Manual

236 Backup, restore, and recovery
3. Enable the FSE partition.
4. Start the recovery of FSC:
For example, to start recovery of the File System Catalog for FSE partition fse_fs01 enter:
When running the fserecover --fsc command the following occurs:
1. If FRI is located on disk, which is the case for all data volumes that are not yet full, recovery is done
from these temporary FRI files.
2. If a data volume on a partitioned FSE medium is full and its FRI has been written to the system volume
on the medium, the recovery is done from FRI on the system volume. This is the fastest method since all
FRI is located on the system volume.
3. If an FSE medium is not partitioned to have a system volume, the recovery is done from FRI on the data
volume, since each data volume includes its own FRI.
The FRI on the data volume is also used if the FRI on the system volume is invalid.
4. If FRI is not available, the recovery process needs to recreate it from file data on the data volume. This
is a time-consuming process since all data need to be read first, and only then can FRI be recreated
and used to recover FSC.
Once FSC recovery is completed, you should run the FSC consistency check as described in ”Consistency
check of FSC vs. HSM file system” on page 178.
HSM file system recovery
HSM file system recovery is necessary in case HSM file system is damaged or corrupted
An HSM file system is recovered directly from the belonging Name Space Catalog (NSC), which is a part
of the File System Catalog. Since the Name Space Catalog contains complete information about the file
system structure (such as the directory structure, file attributes, and security information), the entire HSM file
system structure can be recreated.
Limitations
• Recovery cannot properly handle user changes on an HSM file system that occurred after the last
migration is finished. To prevent this situation, you need to format the HSM file system.
• Symbolic links cannot be recovered because they are not migrated to FSE media.
• Recovery of Windows Alternate Data Streams (ADS) data is not supported, except for the names of
ADS, which are stored in NSC.
Prerequisite
• The Name Space Catalog (NSC) of the FSE partition whose HSM file system will be recovered must
exist.
Name Space Catalog (NSC) was introduced in the FSE release 2.1 and should have been created
during upgrade of the FSE software to that FSE release.
The HSM file system recovery procedure
Linux specific
To recover an HSM file system on a Linux FSE client:
1. From the local /etc/fstab file, determine the device (block special device node) of the HSM file
system, and run the following command:
2. Format the HSM file system using the mkfs.ext3 command. For more information, see the FSE
installation guide for Linux, chapter ”Preparing file systems for FSE”, section ”Creating file systems on
top of LVM logical volumes”.
fserecover --fsc PartitionName
fserecover --fsc fse_fs01
# umount Device