IBM TotalStorage NAS 300, Справочник пользователя

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When a volume is moved between nodes during a failover operation, then PSM
must perform persistent image loading and mapping on the node to which the
volume is moving, just as it does when the “first node” is restarted.
In the failover scenario, loading must take place before the volume can be
brought online on the node (when the clustered disk resource is shown as being
Online in Cluster Administrator). Then, as in the restart case, mapping begins five
minutes after the volume comes online.
Microsoft Cluster Server, which controls the disk resource failover, waits a certain
period, called the pending timeout, for the disk to come online. (During the
loading phase, the disk resource is shown as being in
Online Pending state.)
With a default value of 180 seconds (3 minutes) for the pending timeout, this
time interval might be exceeded because of the time it takes to load the
persistent images on the volume. If this occurs, the delay might cause Cluster
Server to mark the disk as
Failed and to not be available to either NAS Gateway
300 node. Other dependent resources (IP addresses, network names, file shares,
and so on) might also fail.
For this reason, it is recommended that you increase the pending timeout value
for all clustered resources to 1200 seconds (20 minutes). To do this, open
Cluster Administrator, select
Resources from the left pane to display all clustered
resources in the right pane, and then for each resource listed in the right pane:
1. Right-click the resource name and select Properties .
2. Select the Advanced tab.
3. Change the Pending timeout value to 1200 (seconds).
4. Click Apply ; then click OK .
v PSM imposes a limit of 1 terabyte (TB) of cached data, across all volumes on the
NAS Gateway 300. For this reason, you should ensure that the total configured
size of all cache files on the NAS Gateway 300 is not greater than 1 TB.
You can do this by accessing Persistent Storage Manager, then going to the
Volume Settings page, and making sure that the total of all values in the Cache
Size column is 1 TB or less. (You can access Persistent Storage Manager
through the Persistent Storage Manager link on the IBM NAS Admin console on
the NAS Gateway 300 desktop, or by starting the Windows 2000 for Network
Attached Storage user interface and then selecting
Disks , then Persistent
Storage Manager .)
If the total is greater than 1 TB, you should reduce the size of the cache on one
or more of the volumes by selecting the volume from the list, then clicking
Configure , and then selecting a smaller value from the “Cache size” drop-down
list and clicking OK .
Note: You cannot change the size of the cache on a volume that has persistent
images. You must delete all persistent images on the volume before
changing the cache size. You should try to reduce the cache size on a
volume that has no persistent images, if possible, before deleting any
persistent images.
If more than 1 TB of cache is configured on the NAS Gateway 300, the following
can occur (note that a volume for which a persistent image has never been
created is considered to have a cache size of zero, regardless of how large its
cache is configured to be):
– When the NAS Gateway 300 is restarted, PSM prevents a volume from being
mounted on the file system (prevents it from being accessible) if that volume’s
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NAS Gateway 300 User’s Reference