User's Manual

hp StorageWorks File System Extender User Guide 121
regular release. The release job is stopped when the low watermark is reached or if there are no more
files on the release candidate list that match the specified criteria.
• Situation 2
A critical watermark is reached on the HSM file system. In this case, all files on the release candidate
list (regardless of their size and retention time) are scheduled for forced release. The release job is
stopped when the high watermark is reached or if there are no more files to release.
In both cases, the files that are on the release candidate list and were not released during the most recent
release job remain on the top of the release candidate list.
Default release policy
Note that the default release policy does not include the ExcludeFromRelease variable. If you do not
configure this variable, all files are considered for release according to the other release policy parameters
specified while configuring the FSE partition.
Default release policy is defined in the FSE configuration template for FSE partition configuration. For
details, see ”Template for FSE partitions - Release part” on page 249.
Recall
A recall job is started on a request for a read or write operation on an offline file. The contents of the file
are then retrieved from the FSE medium and copied back to the HSM file system. The only parameter for
the recall configuration is the timeout value.
Recall behavior is automated to the extent that recall is retried from alternative copies in cases that a
resource allocation is affected. This usually happens when a medium is corrupted and marked in the
Resource Management Database accordingly as unusable, or when a hardware error occurred and the
drive is marked as bad.
In such cases, the recall job requests new resources to perform the operation until reading from the tape is
successful, or all resources (media that contain respective data copies or drives) are exhausted. In this latter
event, the recall job fails.
NOTE: An error message is issued regardless of the recall retry if the recall lasts longer than specified
with the RecallTimeOut parameter. However, when resource allocation is disturbed as described, this
parameter is ignored and recalling a file succeeds if any copy is available.
Recall parameters
There is only one configurable parameter for the recall policy.
Recall timeout (RecallTimeout)
Definition When a user requests an offline file, the RecallTimeout is the time given to FSE to
bring an offline file back online. If FSE cannot bring the file online in this time, the user is
notified that the file is unavailable and the request is discarded.
Impact Set the value according to the load of the FSE implementation. The value can be lower if
your system performance is optimized. If the load of the FSE implementation is significant
and the value is low, the following can happen:
• At the defined time all drives are in use.
• There is a significant number of jobs with a higher priority already running.
• The needed medium cannot be found (it is offline).
In such cases, the HSM notifies the user that the file is not available.