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

6.1.2 Online Backup (by Slice Detachment)

For mirror volumes, data can be backed up using snapshots by detaching slices during the services operation.

For use conditions on snapshots by detaching a slice, see "Creating a Snapshot by Detaching Slice."

To secure consistency of data in a detached slice, the services must be stopped temporarily when detaching the slice.

For securing consistency of snapshot data, see "Ensuring Integrity of Snapshot Data."

 

1) Stop the services

1a) With a shared volume used by a cluster application, exit the cluster application.

1b) With a volume not used by a cluster application

1b-1) Stop the services using the volume.

1b-2) When the volume is used as a file system, unmount the file system. The following shows an example when the mount point is /mnt1.

# cd /
# umount /mnt1

 

2) Detaching the slice

Detach the slice from the mirror volume. The following shows an example of detaching the slice from disk Disk1.

# sdxslice -M -c Class1 -d Disk1 -v Volume1

When using GDS Management View, see "Slice Detachment" in "Backup (by Slice Detachment)."

 

3) Resuming the services

3a) With a shared volume used by a cluster application, execute the cluster application.

3b) With a volume not used by a cluster application

3b-1) When the volume is used as a file system, mount the file system. The following shows an example when the mount point is /mnt1.

• For a ext3 file system

  # mount -t ext3 /dev/sfdsk/Class1/dsk/Volume1 /mnt1

3b-2) Resume the services.

 

4) When the volume is used as a file system, check and repair consistency of the file system. If the file system was unmounted when the slice was detached in step 1), this step can be skipped.

• For a ext3 file system

  # fsck -t ext3 -y /dev/sfdsk/Class1/dsk/Disk1.Volume1

   

5) Backing Up

Back up data in the detached slice. The following shows an examples of backing up data to a tape medium of tape device /dev/st0.

For details about the backup method, see manuals of a file system to be backed up and used commands.

• When backing up data held in a raw device with the dd(1) command

  # dd if=/dev/sfdsk/Class1/rdsk/Disk1.Volume1 of=/dev/st0 bs=32768

   

6) Re-attaching the slice

Re-attach the detached slice to the mirror volume.

# sdxslice -R -c Class1 -d Disk1 -v Volume1

When using GDS Management View, see "Attach Slice" in "Backup(by Slice Detachment)."