Storing xp snapshot data – HP StorageWorks XP Remote Web Console Software User Manual
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Use the XP Business Copy's Pair Operation window to see the status of the volume. Using RAID
Manager, you can check the volume status by the pairdisplay command, but you cannot
distinguish between an SMPL volume and an SMPL(PD) volume. To distinguish between an SMPL
volume and an SMPL(PD) volume by using RAID Manager, you need to issue the inqraid command
as well. The inqraid command will show you whether or not the volume is being used by XP
Snapshot. As a result of the inqraid command, if the volume is not used by XP Snapshot, the
volume status is SMPL. If the volume is used by XP Snapshot, the status of the volume is SMPL(PD).
NOTE:
When using the inqraid command specify the -fw option of the XP Snapshot pair IDs
from 3 to 63.
Storing XP Snapshot Data
XP Snapshot data is a replica of data in the P-VOL of an XP Snapshot pair, and is stored in a pool.
When the P-VOL is updated, the updated part of the data is copied to the pool as snapshot data
before the P-VOL is updated. This process is called storing snapshot data.
If you issue a command to an XP Snapshot pair to store snapshot data, the snapshot data will be
stored in the pool later, at the time a host makes a write request to the P-VOL of an XP Snapshot
pair. An XP Snapshot pair can store up to 64 snapshot data per a P-VOL.
To store snapshot data, you can use the RAID Manager command.
You can also store snapshot data for each consistency group by using RAID Manager. When you
store snapshot data by consistency group, data is copied as of the same point in time for all P-VOLs
in the group.
shows an overview of storing snapshot data by a consistency
group.
Figure 4 Overview of Storing XP Snapshot Data by a Consistency Group
When an XP24000/XP20000 Disk Array accepts the command from RAID Manager, which
requests storing the data by a consistency group (1 in
), all status of the XP
Snapshot pairs in the corresponding consistency group will change to PSUS (2 in
). After that, when the host issues write I/O request to each P-VOL in the corresponding
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About XP Snapshot Operations