Workflow for resolving insufficient pool capacity, Pool capacity calculations, Workflow for creating a backup of data – HP XP7 Storage User Manual
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Related topics
•
“Shared memory requirements” (page 28)
Workflow for resolving insufficient pool capacity
If the pool capacity is insufficient, the storage system can suspend FS pairs (“PSUE” status).
Use the following workflow to resolve an insufficient pool capacity:
1.
Estimate the capacity of snapshot data to be copied to the pool.
If the capacity of snapshot data to be copied to the pool varies hour by hour, ensure that the
largest capacity is your pool capacity.
2.
Assign the pool capacity based on the estimate.
Pool capacity calculations
To decide the capacity of pools, estimate the capacity of snapshot data to be copied using the
following formula:
The capacity of snapshot data to be copied = The capacity of data written
to the same area in the P-VOL during the period from when snapshot data
is stored to when the snapshot data is deleted
Although the pool capacity is decided according to the estimation, if the pool capacity exceeds
the threshold, address the issue.
Related topics
•
For more information about addressing exceeding the threshold issues, see
.
•
“Fast Snap data pool requirements” (page 30)
Workflow for creating a backup of data
You can create a backup of data using FS. The target for the backup is only the areas where the
snapshot data is stored. You can create a backup copy even if the pool capacity is small.
NOTE:
During this process, a significant amount of data is read from the S-VOL. This can increase
access to the P-VOL and degrade the host I/O performance.
Use the following workflow to create a backup of data:
1.
Store the snapshot data (see
“Splitting Fast Snap pairs to store snapshot data” (page 73)
).
2.
Use an S-VOL.
External Storage and external volumes used as pool-VOLs
You can use External Storage (Ext Stor) to connect a XP7 storage system to other storage systems.
In Ext Stor, a XP7 storage system is referred to as a local storage system and the other storage
systems are referred to as external storage systems.
With Ext Stor installed, you can use external and internal volumes as pool-VOLs. Volumes in local
storage systems are referred to as internal volumes and volumes in external storage systems are
referred to as external volumes.
NOTE:
Using external volumes increases the likelihood of a failure, and disaster recovery is more
complex and challenging. Using multiple external volumes as pool-VOLs in a pool increases the
likelihood of the pool being blocked.
To minimize the adverse effects of failure, use only one pool per external storage system. An
external pool-VOL that is blocked due to a failure blocks the pool. You must restore blocked pools.
Requirements for Fast Snap tasks
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