Brocade Network Advisor SAN User Manual v12.3.0 - Manual (Page 913)

Brocade Network Advisor SAN User Manual 861
53-1003154-01
Thin provisioned LUNs
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3. Click Refresh periodically to update the display.
Thin provisioned LUNs
With the introduction of Fabric OS 7.1.0, the switch can discover if a disk LUN is a thin provisioned
LUN. Support for a thin provisioned LUN is limited to disk containers only. Thin provisioned LUNs
can be created with the new LUN option.
NOTE
Currently, thin provisioned LUN support is limited to Brocade-tested storage arrays running specific
supported firmware releases. The thin provisioned LUN status will be displayed as Yes for supported
storage arrays only.
Thin provisioned LUNs rely on on-demand allocation of blocks of data, instead of the traditional
method of allocating all blocks up front. If a thin provisioned LUN status is shown as Yes, then
first-time encryption and rekey are done on the allocated blocks only, which results in the
provisioned region of the LUN to remain the same after the rekey is performed.
Thin provisioned LUN support requires no action by the user. The switch can automatically detect if
a LUN is a thin provisioned LUN.
NOTE:
• For thin provisioned LUNs that were previously full provisioned then converted to thin, a
discoverLUN command must be performed prior to any rekeying operations. Failure to do so
results in the full capacity of the LUN to be encrypted as if it were not thin provisioned.
Updated thin provisioned status can be verified using the cryptocfg
--
show
-
container
-
all
-
stat command and checking the output for “
Thin Provision LUN: Yes
”. Similarly, if a thin-
to full-LUN conversion has been performed, a discoverLUN command must be performed for
this LUN change to reflect on the switch or blade.
• If a LUN is a thin provisioned LUN, LUN status is shown as Yes. (Thin provision support is
limited to Brocade-tested storage arrays. The thin provisioned LUN status will be displayed as
Yes for supported storage arrays only.)
• If a LUN is not a thin provisioned LUN or if thin provisioning is not supported with the LUN, LUN
status is shown as No. (This can be a result of the array not supporting thin provisioning, or the
switch or blade does not support the thin provisioning features of the array. Refer to the Fabric
OS release notes for supported arrays.)
• If LUN status cannot be determined, LUN status is shown as Unknown.
• If you are running a Fabric OS version earlier than v7.1.0, LUN status is shown as Not
Applicable.
• Zero detect with encryption is not supported.
Thin Provisioning support
Thin-provisioned logical unit numbers (LUNs) are increasingly used to support a pay-as-you-grow
strategy for data storage capacity. Also known as dynamic provisioning, virtual LUNs, or thin LUNs,
the same technology that allows storage administrators to allocate physical disk space to LUNs on
an as-needed basis creates limitations around certain data-at-rest encryption operations that use
the switch or blade. Performing first-time encryption (FTE) (conversion of cleartext to ciphertext)
and data rekeying operations (applying new data encryption keys to ciphertext data) on