March 2013
Dell EqualLogic Configuration Guide v14.1
5-40
•
Snapshot reserve space for any volume can be decreased at any time. The minimum size
allowed is based on the current space used by existing snapshots using the snapshot reserve.
•
Snapshot reserved space for any volume can be increased at any time assuming there is
available free space in the storage pool hosting the volume.
5.3.1
Clones
Cloning creates a new volume by copying an existing volume. The new volume has the same
reported size, contents and thin-provision settings as the original volume. You can clone a regular
volume, a specific replica of a volume, or a specific snapshot of a volume.
•
Volume clones use non-shared storage (unlike snapshots)
•
Volume clones reduce the amount of storage pool free space
•
All regular volume operations can be performed on the clone once the cloning operation is
complete.
•
The cloning operation supports instant accessibility (while the clone operation is occurring)
Table 18 shows clone sources and properties.
Table 18
Cloning modes and properties
Clone source
Common properties
Clone from Volume
•
Creates a new volume
•
Creates a new volume name
•
Creates a new iSCSI target IQN
•
Has same reported size as source volume
•
Has same contents as source volume
•
Cloned volume is immediately available
•
Cloning consumes free pool space equivalent to 100% of the
volume reserve setting for the source volume
(a)
Clone from
Snapshot
Clone from Inbound
Replica
(a)
(secondary group)
(a)
Replica clones are created in the secondary group pool and are immediately available at the
secondary group IP address.
5.4
Thin provisioning
Thin provisioned volumes provide administrators with an additional option for managing data growth
within the SAN. Thin provisioning allows volumes to present a logical capacity to the host(s)
connecting to the volume that is different (larger) than the actual physical storage resource allocation
used by the volume at any given time.
Note:
Volumes automatically created and managed by the NAS Service inside the NAS
Reserve pool used by an FS Series appliance are fully allocated at creation and cannot be
thin provisioned. Once those volumes are created (when the NAS Reserve is created they
cannot be shrunk.
A volume can be provisioned as a thin provisioned volume at creation or after creation. The following
rules apply to thin provisioned volumes:
