Hardware manual

Group Administration Advanced volume operations
10–3
Enabling thin provisioning on a volume
When you create a new volume or clone an existing volume, you can enable thin provisioning on the volume. In
addition, you can modify an existing volume and enable thin provisioning.
Thin provisioning is not appropriate for all environments or vo
lumes. You must fully understand thin provisioning
before implementing the functionality on a volume. See About thin provisioning on page 1
0-1.
When enabling thin provisioning on an existing volume, be aware of
these issues:
• Enabling thin provisioning on a volume usually decreases the amount of space
that the group allocates to the
volume (called the volume reserve).
• Enabling thin provisioning changes the amount of allocated snapshot space
and replication space, because the
group allocates snapshot space and replication space based on a percentage of the volume reserve.
However, the group increases the snapshot space an
d replication space percentages to prevent the deletion of
snapshot or replication data.
To enable thin provisioning on
an existing volume:
1. Click
Volumes in the lower-left panel, then expand Volumes, then select the volume, then click Modify
settings
, and then click the Space tab.
2. In the Modify volume settings – Space dialog box, se
lect Thin-provisioned volume. The Pool Space table
values change.
3. Optionally, use the sliders to modify the group-wide default thin provisioning space
settings:
• Minimum volume reserve
• In-use space warning limit
• Maximum in-use space (maximum volume reserve
)
See Thin provisioning space settings on pag
e 10-2.
4. Click
OK.
Make sure you carefully monitor the space usage for a thin-provisioned volume. Se
e Monitoring volumes,
collections, and snapshots on page 1
5-24.
Disabling thin provisioning on a volume
You can disable thin provisioning on a standard volume.
Restriction: Yo
u cannot disable thin provisioning on a template volume, thin clone volume, recovery
template volume, or a recovery thin clone volume.
Before disabling thin provisioning,
consider the following:
• If you disable thin provisioning on a volume, the group allocates the full reported volume size (the reported
size
and the volume reserve is the same). Therefore, you must have sufficient free pool space.