PRIMECLUSTER Global Disk Services Configuration and Administration Guide 4.1 (Solaris(TM) Operating System)
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Chapter 6 Backing Up and Restoring> 6.4 Online Backup and Instant Restore through Proxy Volume

6.4.2 Online Backup (Snapshot by OPC)

If GDS Snapshot is installed in a system where a disk array unit with the OPC function is used, backup can be performed through instant snapshot by OPC using proxy volumes without stopping services.

However, to secure consistency of snapshot data, the services must be stopped temporarily when creating a snapshot (when updating proxy volumes).


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

[Figure: Backup Schedule]


Background Copy (OPC Physical Copy) and Backup to Tape
During the copying process, data can be backed up to tape, but the backup will impose the load on the disk array unit and may affect services using master volumes.

 

Instant Snapshot by OPC
For use conditions of instant snapshot by OPC, see "Instant Snapshot by OPC." If proxy volumes are in mirroring configuration with the multiplicity of two or higher, the OPC function is unavailable for copying data from master volumes to the proxy volumes. For details, see "Using the Advanced Copy Function in a Proxy Configuration."

Procedure

1) Relating a proxy volume

Before creating snapshots, relate proxy volume Volume2 as a copy destination to master volume Volume1. In this example, Volume1 and Volume2 belong to class Class1. Execute the following command on a node that belongs to the scope of Class1.

# sdxproxy Relate -c Class1 -m Volume1 -p Volume2



When using GDS Management View, see "Relate."

GFS Local File System in Multi-partition Configuration
If multiple volumes constitute one GFS Local File System, relate the proxy volume to all of the volumes.

 

2) Stopping the proxy volume

Stop proxy volume Volume2. If Class1 is a shared class, specify the "-e allnodes" option to stop Volume2 on all nodes.

# sdxvolume -F -c Class1 -v Volume2



When using GDS Management View, select a proxy volume and execute [Operation]:[Stop Volume] in the Main Screen.

 

3) Stopping the services

To secure consistency of snapshot data, stop the services before creating a snapshot and restrain the master volume from being written in.

3a) When the master volume is being used for a cluster application

Inactivate the cluster application.

3b) When the master volume is not being used for a cluster application

3b-1) Stop the services for which the master volume is being used.

3b-2) When the master volume is used as a file system, use either the following methods to prevent write access to the file system. In the following examples, the mount point is /DATA.

4) Updating the proxy volume

Copy data from master volume Volume1 to proxy volume Volume2 with the OPC function to update Volume2 with the data of Volume1 at the moment. Execute the following command on a node that belongs to the scope of class Class1.

# sdxproxy Update -c Class1 -p Volume2 -e instant


When returning from the command, the update of Volume2 will be complete. Subsequently, background OPC physical copying is performed, but you may go on to step 5) without waiting until the copying is complete.


When using GDS Management View, see "Update" in "Backup (by OPC)." For setting of the update environment, select "Yes" to "Instant Snapshot."

GFS Local File System in Multi-partition Configuration
Update proxy volumes for all the volumes that constitute the file system.

 

5) Resuming the services

5a) When the master volume is used for a cluster application

Activate the cluster application.

5b) When the master volume is not used for a cluster application

5b-1) When the master volume is used as a file system, use either the following methods to permit write access from applications to the file system on master volume Volume1. In the following examples, the mount point is /DATA.


5b-2) Start the services for which the master volume is used.

 

6) Starting the proxy volume

Start proxy volume Volume2 on a node where backup to tape is performed.

# sdxvolume -N -c Class1 -v Volume2



When using GDS Management View, select a proxy volume and execute [Operation]:[Start Volume] in the Main Screen.

 

7) Confirming the completion of copying

Confirm that the copying is complete.

# sdxinfo -S -c Class1 -o Volume2

OBJ    CLASS   GROUP   DISK    VOLUME   STATUS
-----  ------  ------  ------  -------  -------
slice  Class1  Group2  Disk3   Volume2  ACTIVE
slice  Class1  Group2  Disk4   Volume2  ACTIVE


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

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

 

8) Backing up to tape

Back up the snapshot data on the proxy volume to tape. Execute the following commands on a node that belongs to the scope of class Class1.


For details on the backup methods, see the manuals of file systems to be backed up and used commands.

8a) When backing up data held in a raw device with the dd(1M) command

# dd if=/dev/sfdsk/Class1/rdsk/Volume2 of=/dev/rmt/0 bs=32768


8b) When backing up the ufs file system with the tar(1) command

8b-1) Before mounting

Check and repair consistency of the ufs file system on the proxy volume with the fsck(1M) command. When the file system on the master volume was unmounted in step 3b-2), skip this step.

# fsck -F ufs /dev/sfdsk/Class1/rdsk/Volume2


8b-2) Mounting the snapshot

Mount the ufs file system on proxy volume Volume2 on temporary mount point /DATA_backup.

# mkdir /DATA_backup
# mount -F ufs /dev/sfdsk/Class1/dsk/Volume2 /DATA_backup


8b-3) Backing up to tape

This example shows the procedure when data is backed up to a tape medium of tape device /dev/rmt/0 with the tar(1) command.

# cd /DATA_backup
# tar cvf /dev/rmt/0 .


8b-4) Unmounting the snapshot

Unmount the file system mounted in step 8b-2).

# cd /
# umount /DATA_backup
# rmdir /DATA_backup


8c) When backing up the ufs file system with the ufsdump(1M) command

8c-1) Before mounting

Check and repair consistency of the ufs file system on the proxy volume with the fsck(1M) command. When the file system on the master volume was unmounted in step 3b-2), skip this step.

# fsck -F ufs /dev/sfdsk/Class1/rdsk/Volume2


8c-2) Backing up to tape

This example shows the procedure when data is backed up to a tape medium of tape device /dev/rmt/0 with the ufsdump(1M) command

# ufsdump 0ucf /dev/rmt/0 /dev/sfdsk/Class1/rdsk/Volume2


8d) When backing up the sfxfs file system (GFS Local File System) with the tar(1) command

8d-1) Reconfiguring partition information

Reconfigure partition information of the sfxfs file system (GFS Local File System) on proxy volume Volume2.

# sfxadm /dev/sfdsk/Class1/rdsk/Volume2


GFS Local File System in Multi-partition Configuration
For the sfxadm(1M) command, specify device special file names of all the volumes that constitute the file system.

8d-2) Before mounting

Check and repair consistency of the sfxfs file system (GFS Local File System) on proxy volume Volume2 with the fsck(1M) command. When the file system on the master volume was unmounted in step 3b-2), skip this step.

# fsck -F sfxfs /dev/sfdsk/Class1/rdsk/Volume2


GFS Local File System in Multi-partition Configuration
For the fsck(1M) command, specify a device special file name of the representative partition.

8d-3) Mounting the snapshot

Mount the sfxfs file system (GFS Local File System) on proxy volume Volume2 on temporary mount point /DATA_backup.

# mkdir /DATA_backup
# mount -F sfxfs /dev/sfdsk/Class1/dsk/Volume2 /DATA_backup


GFS Local File System in Multi-partition Configuration
For the mount(1M) command, specify a device special file name of the representative partition.

8d-4) Backing up to tape

This example shows the procedure when data is backed up to a tape medium of tape device /dev/rmt/0 with the tar(1) command.

# cd /DATA_backup
# tar cvf /dev/rmt/0 .


8d-5) Unmounting the snapshot

Unmount the file system mounted in step 8b-3).

# cd /
# umount /DATA_backup
# rmdir /DATA_backup


8e) When backing up the sfxfs file system (GFS Local File System) with the sfxdump(1M) command

8e-1) Reconfiguring partition information

Reconfigure partition information of the sfxfs file system (GFS Local File System) on proxy volume Volume2.

# sfxadm /dev/sfdsk/Class1/rdsk/Volume2

GFS Local File System in Multi-partition Configuration
For the sfxadm(1M) command, specify device special file names of all the volumes that constitute the file system.

8e-2) Before mounting

Check and repair consistency of the sfxfs file system (GFS Local File System) on proxy volume Volume2 with the fsck(1M) command. When the file system on the master volume was unmounted in step 3b-2), skip this step.

# fsck -F sfxfs /dev/sfdsk/Class1/rdsk/Volume2


GFS Local File System in Multi-partition Configuration
For the fsck(1M) command, specify a device special file name of the representative partition.

8e-3) Backing up to tape

This example shows the procedure when data is backed up to a tape medium of tape device /dev/rmt/0 with the sfxdump(1M) command.

# sfxdump 0ucf /dev/rmt/0 /dev/sfdsk/Class1/rdsk/Volume2

GFS Local File System in Multi-partition Configuration
For the sfxdump(1M) command, specify a device special file name of the representative partition.

 

9) Stopping the proxy volume

After backing up to tape, stop Volume2 to protect data in proxy volume Volume2. If Class1 is a shared class, specify the "-e allnodes" option to stop Volume2 on all the nodes.

# sdxvolume -F -c Class1 -v Volume2



When using GDS Management View, select a proxy volume and execute [Operation]:[Stop Volume] in the Main Screen.

 

10) Breaking the proxy volume

When no more online backup is to be executed, cancel the relationship between master volume Volume1 and proxy volume Volume2.

# sdxproxy Break -c Class1 -p Volume2


When using GDS Management View, see "Breaking a Proxy."

GFS Local File System in Multi-partition Configuration
Break proxy volumes for all the volumes that constitute the file system

 

11) Re-executing online backup

To perform online backup again, go back to step 3).



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