6.0 HP X9000 File Serving Software File System User Guide (TA768-96043, October 2011)

• File access permissions
• File modification time
Also, no new hard links can be made to the file and the extended attributes cannot be added,
modified, or removed.
The following restrictions apply to directories in a file system enabled for data retention:
• A directory cannot be moved or renamed unless it is empty (even if it contains only normal
files).
• You can delete directories containing only WORM and normal files, but you cannot delete
directories containing retained files.
Retention profiles and retained files
Retained files cannot be deleted until their retention period expires, regardless of the file system
retention policy. You can set a specific retention period for a file; however, it must be within the
minimum and maximum retention periods associated with the file system. If you set a time that is
less than the minimum retention period, the expiration time of the period will be adjusted to match
the minimum retention period. Similarly, if the new retention period exceeds the maximum retention
period, the expiration time will be adjusted to match the maximum retention period. If you do not
set a retention period for a file, the default retention period is used. If that default is zero, the file
will not be retained.
A retention profile also includes a retention mode that controls how the expiration time for the
retention period can be adjusted.
• Enterprise. The expiration date of the retention period can be extended to a later date.
• Relaxed. The expiration date of the retention period can be moved in or extended to a later
date.
Data validation scans
To ensure that WORM and retained files remain unchanged, it is important to run a data validation
scan periodically. Circumstances such as the following can cause a file to change unexpectedly:
• System hardware errors, such as write errors
• Degrading of on-disk data over time, which can change the stored bit values, even if no
accesses to the data are performed
• Malicious or accidental changes made by users
A data validation scan computes hash sum values for the files in the scanned file system or
subdirectory and compares them with the values originally computed for the files. If the scan
identifies changes in the values for a particular file, an alert is generated on the GUI. You can then
replace the bad file with an unchanged copy from an earlier backup or from a remote replication.
The time required for a data scan depends on the number of files in the file system or subdirectory.
If there are a large number of files, the scan could take up to a few weeks to verify all content on
storage. A scheduled scan will quit immediately if it detects that a scan of the same file system is
already running.
You can schedule periodic data validation scans, and you can also run on-demand scans.
Enabling file systems for data retention and validation
You can enable a new or an existing file system for data retention and, optionally, validation.
When you enable a file system, you can define a retention profile that specifies the retention mode
and the default, minimum, and maximum retention periods.
Enabling file systems for data retention and validation 113