User's Manual

hp StorageWorks File System Extender User Guide 133
Once mounted, each HSM file system remains mounted all the time, even after the FSE client host is
restarted. A mounted HSM file system, however, can operate in Limited Access Mode (LAM) or Full Access
Mode (FAM). The operational mode depends on whether the FSE processes are running and whether an
FSE administrator decided to switch between the two modes manually.
An HSM file system operates in LAM:
• before the FSE implementation has been started
• after the FSE implementation has been shut down
• while the FSE implementation is fully operational, after the FSE administrator has manually switched
from FAM to LAM using the FSE command-line interface.
An HSM file system operates in FAM:
• after the FSE implementation has been started
• while the FSE implementation is fully operational, after the FSE administrator has manually switched
from LAM to FAM using FSE command-line interface.
In Limited Access Mode, FSE users and third-party applications can only browse the HSM file system
directory tree and access files that are still online. They cannot modify existing data, add new directories
and files, or recall offline files. If an application tries to access a file while the HSM file system is operating
in LAM, it receives an error. If LAM is manually set for an HSM file system while all FSE processes are
running, the HSM process continues to trigger migrations, releases and deletions on this HSM file system,
according to the migration, release, and deletion policies that are configured for the appropriate FSE
partition.
In contrast, Full Access Mode does not constrain FSE users in any way. All data movement processes are
enabled and you can use all the features that are generally available for HSM file systems in the FSE
implementation.
NOTE: LAM and FAM are compatible with both regular and WORM FSE partitions. When an HSM file
system is operating in FAM, WORM is fully supported, while when operating in LAM, the LAM restrictions
prevail over the configured WORM policies.
For information on how to switch manually between the HSM file system access modes, see ”Switching the
access mode for an HSM file system” on page 138.
NOTE: For information on how to determine the access mode for a particular HSM file system or
troubleshoot potential problems with disk volume access, see description of the fse command in the FSE
command-line reference.