Dell EqualLogic PS6210XS EqualLogic Group Manager Administrator s Guide PS Ser - Page 146

Set a Volume or Snapshot with Lost Blocks Online, Volume and Snapshot Status, disabledeletenotify

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To check the current setting of unmapping, issue the following command: fsuitl behavior query disabledeletenotify NOTE: The disabledeletenotify setting is a global operating system setting that not only disables unmap operations from being sent to the PS Series storage arrays, but also disables TRIM to SSDs. For more information about the fsutil utility, see: technet.microsoft.com/en-us/library/cc785435(v=ws.10).aspx Automatic defrag can generate a large number of unmap operations, which are not recommended for replicated volumes. Therefore, in Windows Server 12, turn off automatic defrag for replicated volumes. Set a Volume or Snapshot with Lost Blocks Online In rare circumstances, a volume (or snapshot) might lose blocks. For example, loss can occur if the power fails and then a control module cache battery fails. (If the control module cache battery is the only power source for a control module for more than 72 hours after a power failure occurs, the battery can fail.) If a volume (or snapshot) loses blocks, the current status of the volume (or snapshot) is offline-lost-cached-blocks. In addition, the group generates an event message. You can choose to set the volume online but retain the lost blocks. If an application tries to read a lost block, an error occurs. If an initiator writes new data to a lost block before it is read, the block is no longer lost. The members containing lost blocks have a status of RAID lost blocks until initiators write to all the lost blocks. NOTE: Setting a volume with lost blocks online is a data integrity risk. The blocks might contain old or invalid data. To manage a volume or snapshot with lost blocks: 1. Click Volumes. 2. Expand Volumes and then select the volume name. 3. Click the Status tab. 4. Click offline-lost-cached-blocks. 5. Either: • Click Set the volume online but retain the lost blocks to set the volume or snapshot online but keep the lost blocks. The volume (or snapshot) status changes to online-lost-blocks. • Click Mark the lost blocks valid and set the volume online to set the lost block status to valid. The volume (or snapshot) status changes to online. The status of the members containing volume data changes to online. 6. Click OK. Volume and Snapshot Status Table 35. Current Volume and Snapshot Status shows status values for volumes and snapshots, and provides solutions for any problems. Table 35. Current Volume and Snapshot Status Status Description Solution online Administrator set the volume or snapshot online, None needed; informational. Online volumes and and no failures have occurred. snapshots are shown in the far-left panel in black text. offline Administrator set the volume or snapshot offline. None needed; informational. Computers cannot access the volume or snapshot, but no failures have occurred. Offline volumes and snapshots are shown in the far-left panel in gray text. 146 About Volumes

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To check the current setting of unmapping, issue the following command:
fsuitl behavior query disabledeletenotify
NOTE: The
disabledeletenotify
setting is a global operating system setting that not only disables unmap
operations from being sent to the PS Series storage arrays, but also disables TRIM to SSDs. For more information about
the
fsutil
utility, see:
technet.microsoft.com/en-us/library/cc785435(v=ws.10).aspx
Automatic defrag can generate a large number of unmap operations, which are not recommended for replicated volumes. Therefore,
in Windows Server 12, turn
off
automatic defrag for replicated volumes.
Set a Volume or Snapshot with Lost Blocks Online
In rare circumstances, a volume (or snapshot) might lose blocks. For example, loss can occur if the power fails and then a control
module cache battery fails. (If the control module cache battery is the only power source for a control module for more than 72
hours after a power failure occurs, the battery can fail.)
If a volume (or snapshot) loses blocks, the current status of the volume (or snapshot) is
offline-lost-cached-blocks
. In
addition, the group generates an event message.
You can choose to set the volume online but retain the lost blocks. If an application tries to read a lost block, an error occurs. If an
initiator writes new data to a lost block before it is read, the block is no longer lost. The members containing lost blocks have a status
of
RAID lost blocks
until initiators write to all the lost blocks.
NOTE: Setting a volume with lost blocks online is a data integrity risk. The blocks might contain old or invalid data.
To manage a volume or snapshot with lost blocks:
1.
Click
Volumes
.
2.
Expand
Volumes
and then select the volume name.
3.
Click the
Status
tab.
4.
Click
offline-lost-cached-blocks
.
5.
Either:
•
Click
Set the volume online but retain the lost blocks
to set the volume or snapshot online but keep the lost blocks. The
volume (or snapshot) status changes to
online-lost-blocks
.
•
Click
Mark the lost blocks valid and set the volume online
to set the lost block status to valid. The volume (or snapshot)
status changes to
online
. The status of the members containing volume data changes to
online
.
6.
Click
OK
.
Volume and Snapshot Status
Table 35. Current Volume and Snapshot Status
shows status values for volumes and snapshots, and provides solutions for any
problems.
Table 35. Current Volume and Snapshot Status
Status
Description
Solution
online
Administrator set the volume or snapshot online,
and no failures have occurred.
None needed; informational. Online volumes and
snapshots are shown in the far-left panel in
black text.
offline
Administrator set the volume or snapshot
offline.
None needed; informational. Computers cannot
access the volume or snapshot, but no failures
have occurred.
Offline
volumes and snapshots
are shown in the far-left panel in gray text.
146
About Volumes