D.19 Snapshot Creation Using Command

PRIMECLUSTER Global Disk Services Configuration and Administration Guide 4.1 (Linux)

D.19 Snapshot Creation Using Command

In this section, operation outline of snapshot creation using command is explained. Please use it as a reference when configuring the environment. For details, see the Command Reference.

1) Joining the proxy volume with master volume

Join the proxy volume with the master volume, and copy the master volume data to the proxy volume. Before joining them, stop the proxy volume.

Example) Master volume Volume1 and proxy volume Volume2 will be joined.

# sdxvolume -F -c Class1 -v Volume2
# sdxproxy Join -c Class1 -m Volume1 -p Volume2

After returning from the command, synchronization copying will automatically be performed.

If Class1 is a shared class, use the -e allnodes option with the sdxvolume -F command to stop Volume2 on all the nodes within the class scope.
-m option and -p option can indicate groups as well as volumes. When indicating a group, all volumes within the group will be copied.

2) Confirming the completion of copying

Confirm that the synchronization copying is complete.

Example) Confirming synchronization copying of proxy volume (Volume2) is complete.

# sdxinfo -S

OBJ    CLASS   GROUP   DISK    VOLUME   STATUS
------ ------- ------- ------- -------  --------
slice  Class1   Group1  Disk1   Volume1  ACTIVE
slice  Class1   Group1  Disk2   Volume1  ACTIVE
slice  Class1   Group2  Disk3   Volume2  STOP
slice  Class1   Group2  Disk4   Volume2  STOP

If all the displayed slices' STATUS fields are "STOP", synchronization copying is complete.

If the synchronization copying is still in progress, "COPY" will be displayed in the STATUS field.

3) Creating a snapshot

In order to create a snapshot, part the proxy volume from the master volume after confirming that synchronization copying is complete.

# sdxproxy Part -c Class1 -p Volume2

In order to create a snapshot properly, you should either stop the application, or secure integrity at the file system layer or database layer that is managing the data.

For instance, if you are using the file system, use the umount(8) command to unmount the file system before separating the proxy volume from the master volume.

4) Creating a backup

In order to make a data backup from the snapshot you created, follow the procedures of whatever backup tool you are using.

If you are not using the snapshot function after creating the backup, cancel the master-proxy relationship.

5) Rejoining the proxy volume with master volume

In order to synchronize the proxy volume with the master volume again, remove the created snapshot, and rejoin the proxy volume with the master volume. Before rejoining them, stop the proxy volume.

If Class1 is a shared class, use the -e allnodes option with the sdxvolume -F command to stop Volume2 on all the nodes within the class scope.

# sdxvolume -F -c Class1 -v Volume2
# sdxproxy Rejoin -c Class1 -p Volume2

Synchronization copying will be performed as in step 1).

When creating more than one backup using the same proxy volume, repeat steps 2) to 4).

6) Canceling the master-proxy relationship

Cancel the master-proxy relationship, and finish using the snapshot function.

# sdxproxy Break -c Class1 -p Volume2

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