HP ProLiant DL380G5-WSS 3.7.0 HP StorageWorks HP Scalable NAS File Serving Sof - Page 374

Changing the number of LUNs can cause cluster failure, Recommendations for storage capacity upgrades

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the Management Console or mx utility, and can be used normally from that point forward. If OLI is not possible with your hardware combination, you will need to restart HP Scalable NAS after inserting a new disk. The disk will then be visible to the cluster. Changing the number of LUNs can cause cluster failure HP Scalable NAS uses worldwide names and LUN numbers to associate PSD device names with SAN devices. If the LUN numbers are changed on an array (for example, by combining LUNs or breaking a LUN into multiple LUNs), the cluster can fail to start when servers are rebooted because the PSD device names are no longer associated with the correct LUNs. HP Scalable NAS cannot automatically detect a change in LUN numbering because its identification mechanism uses the worldwide name, which changes as the LUN changes. To minimize downtime, if you need to make changes to your storage which will result in the LUN numbers on the array changing, contact HP Technical Support before making the change. However, if this situation should occur, you can use the mprepair utility to restore the membership partitions. You will then be able to restart the cluster. For assistance in restoring access to PSFS filesystems, contact HP Support. NOTE: LUNs can safely be resized. Problems occur only if LUN numbering on the array is changed. Recommendations for storage capacity upgrades When the drives in a storage array, such as the HP StorageWorks EVA, are being replaced to increase capacity, the array rebalances the data as each drive is replaced. This activity can impact the performance of the active cluster, as the latent I/Os generated by the data rebalancing can trigger HP Scalable NAS timeouts. When planning a disk upgrade process, in addition to following the best practices recommended for your particular array, you should also consider increasing the following HP Scalable NAS timeouts. 374 SAN maintenance

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the Management Console or
mx
utility, and can be used normally from that point
forward.
If OLI is not possible with your hardware combination, you will need to restart HP
Scalable NAS after inserting a new disk. The disk will then be visible to the cluster.
Changing the number of LUNs can cause cluster failure
HP Scalable NAS uses worldwide names and LUN numbers to associate PSD device
names with SAN devices. If the LUN numbers are changed on an array (for example,
by combining LUNs or breaking a LUN into multiple LUNs), the cluster can fail to
start when servers are rebooted because the PSD device names are no longer
associated with the correct LUNs. HP Scalable NAS cannot automatically detect a
change in LUN numbering because its identification mechanism uses the worldwide
name, which changes as the LUN changes.
To minimize downtime, if you need to make changes to your storage which will result
in the LUN numbers on the array changing, contact HP Technical Support before
making the change.
However, if this situation should occur, you can use the
mprepair
utility to restore
the membership partitions. You will then be able to restart the cluster. For assistance
in restoring access to PSFS filesystems, contact HP Support.
NOTE:
LUNs can safely be resized. Problems occur only if LUN numbering on the array is
changed.
Recommendations for storage capacity upgrades
When the drives in a storage array, such as the HP StorageWorks EVA, are being
replaced to increase capacity, the array rebalances the data as each drive is
replaced. This activity can impact the performance of the active cluster, as the latent
I/Os generated by the data rebalancing can trigger HP Scalable NAS timeouts.
When planning a disk upgrade process, in addition to following the best practices
recommended for your particular array, you should also consider increasing the
following HP Scalable NAS timeouts.
SAN maintenance
374