Administrator Guide

Modifying a volume
You can change the name and cache settings for a volume. You can also expand a volume. If a virtual volume is not a secondary
volume involved in replication, you can expand the size of the volume but not make it smaller. If a linear volume is neither
the parent of a snapshot nor a primary or secondary volume, you can expand the size of the volume but not make it smaller.
Because volume expansion does not require I/O to be stopped, the volume can continue to be used during expansion.
The volume cache settings consist of the write policy, cache optimization mode, and read-ahead size. For more information on
volume cache settings, see About volume cache options.
CAUTION: Only change the volume cache settings if you fully understand how the host operating system,
application, and adapter move data so that you can adjust the settings accordingly.
The volume tier affinity settings are No Affinity, Archive, and Performance. For more information about these settings, see
Volume tier affinity features.
To see more information about a volume, hover the cursor over the volume in the table. Viewing volumes contains more details
about the Volume Information panel that appears.
Modify a volume
Perform the following steps to modify a volume:
1. In the Volumes topic, select a volume in the volumes table.
2. Select Action > Modify Volume.
The Modify Volume panel opens.
3. Optional: In the New Name field, type a new name for the volume. A volume name is case-sensitive and can have a
maximum of 32 bytes. It cannot already exist in the system or include the following: " , < \
4. Optional: In the Expand By field, type the size by which to expand the volume. If overcommitting the physical capacity of
the system is not allowed, the value cannot exceed the amount of free space in the storage pool. You can use any of the
following units: MiB, GiB, TiB, MB, GB, TB.
Volume sizes are aligned to 4.2 MB (4 MiB) boundaries. When a volume is created or expanded, if the resulting size is less
than 4.2 MB it will be increased to 4.2 MB. A value greater than 4.2 MB will be decreased to the nearest 4.2 MB boundary.
5. Optional: In the Write Policy list, select Write-back or Write-through.
6. Optional: In the Write Optimization list, select Standard or No-mirror.
7. Optional: In the Read Ahead Size list, select Adaptive, Disabled, Stripe, or a specific size (512 KB; 1, 2, 4, 8, 16, or 32 MB).
8. Optional: In the Tier Affinity field, select No Affinity, Archive, or Performance. The default is No Affinity.
9. Click OK.
If a change to the volume size overcommits the pool capacity, the system prompts you to configure event notification to be
warned before the pool runs out of physical storage.
10. If the virtual volume exceeds the capacity:
a. Click OK to continue. Otherwise, click Cancel. If you clicked OK, the volumes table is updated.
b. To close the confirmation panel, click OK.
Copying a volume or snapshot
You can copy a linear or virtual volume or a virtual snapshot to a new virtual volume.
When using a linear volume as the source, the copy operation creates a transient snapshot, copies the data from the snapshot,
and deletes the snapshot when the copy is complete. If the source is a snapshot, the copy operation is performed directly from
the source; this source data may change if modified data is to be included in the copy and the snapshot is mounted and in use.
To ensure the integrity of a copy, unmount the source or, at minimum, perform a system cache flush on the host and refrain
from writing to the source. Since the system cache flush is not natively supported on all operating systems, it is recommended
to unmount temporarily. The copy will contain all data on disk at the time of the request, so if there is data in the OS cache, that
data will not be copied. Unmounting the source forces the cache flush from the host OS. After the copy has started, it is safe to
remount the source and resume I/O.
Working in the Volumes topic
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