VERITAS Volume Manager identifies a mirrored volume as a plex. A plex can be backed up without unmounting it or taking the entire volume offline. This is done by creating a snapshot copy of the volume and backing up this temporary volume without halting the system or denying user access to the data.
Be sure the cluster is running problem-free before performing the backup procedure.
Log on to any node in the cluster, and become superuser on the current primary node for the disk group on the cluster.
List the disk group information.
# vxprint -g diskgroup |
Run the scstat(1M) command to see which node has the disk group currently imported, indicating it is the primary node for the disk group.
# scstat -D |
Shows the status for all disk device groups.
Create a snapshot of the volume using the vxassist command.
# vxassist -g diskgroup snapstart volume |
Creating a snapshot can take a long time depending on the size of your volume.
Verify the new volume was created.
# vxprint -g diskgroup |
When the snapshot is complete, a status of Snapdone displays in the State field for the selected disk group.
Stop any data services that are accessing the file system.
# scswitch -z -g resource-group[,...] -h ““ |
Stop all data services to ensure that the data file system is properly backed up. If no data services are running, you do not need to perform Step 6 and Step 8.
Create a backup volume named bkup-vol and attach the snapshot volume to it using the vxassist command.
# vxassist -g diskgroup snapshot volume bkup-vol |
Restart any data services that were stopped in Step 6, using the scswitch(1M) command.
# scswitch -z -g resource-group[,...] -h node[,...] |
Verify the volume is now attached to the new volume bkup-vol using the vxprint command.
# vxprint -g diskgroup |
Register the disk group configuration change.
# scconf -c -D name=diskgroup,sync |
Check the backup volume using the fsck command.
# fsck -y /dev/vx/rdsk/diskgroup/bkup-vol |
Perform a backup to copy the volume bkup-vol to tape or another medium.
Use the ufsdump(1M) command or the backup utility you normally use.
# ufsdump 0ucf dump-device /dev/vx/dsk/diskgroup/bkup-vol |
Remove the temporary volume using vxedit.
# vxedit -rf rm bkup-vol |
Register the disk group configuration changes using the scconf(1M) command.
# scconf -c -D name=diskgroup,sync |
In the following example, the cluster node phys-schost-2 is the primary owner of the metaset disk group schost-1, therefore the backup procedure is performed from phys-schost-2. The volume /vo101 is copied and then associated with a new volume, bkup-vol.
[Become superuser on the primary node.] [Identify the current primary node for the disk group:] # scstat -D -- Device Group Servers -- Device Group Primary Secondary ------------ ------- --------- Device group servers: rmt/1 - - Device group servers: schost-1 phys-schost-2 phys-schost-1 -- Device Group Status -- Device Group Status ------------ ------ Device group status: rmt/1 Offline Device group status: schost-1 Online [List the disk group information:] # vxprint -g schost-1 TY NAME ASSOC KSTATE LENGTH PLOFFS STATE TUTIL0 PUTIL0 dg schost-1 schost-1 - - - - - - dm schost-101 c1t1d0s2 - 17678493 - - - - dm schost-102 c1t2d0s2 - 17678493 - - - - dm schost-103 c2t1d0s2 - 8378640 - - - - dm schost-104 c2t2d0s2 - 17678493 - - - - dm schost-105 c1t3d0s2 - 17678493 - - - - dm schost-106 c2t3d0s2 - 17678493 - - - - v vol01 gen ENABLED 204800 - ACTIVE - - pl vol01-01 vol01 ENABLED 208331 - ACTIVE - - sd schost-101-01 vol01-01 ENABLED 104139 0 - - - sd schost-102-01 vol01-01 ENABLED 104139 0 - - - pl vol01-02 vol01 ENABLED 208331 - ACTIVE - - sd schost-103-01 vol01-02 ENABLED 103680 0 - - - sd schost-104-01 vol01-02 ENABLED 104139 0 - - - pl vol01-03 vol01 ENABLED LOGONLY - ACTIVE - - sd schost-103-02 vol01-03 ENABLED 5 LOG - - - [Start the snapshot operation:] # vxassist -g schost-1 snapstart vol01 [Verify the new volume was created:] # vxprint -g schost-1 TY NAME ASSOC KSTATE LENGTH PLOFFS STATE TUTIL0 PUTIL0 dg schost-1 schost-1 - - - - - - dm schost-101 c1t1d0s2 - 17678493 - - - - dm schost-102 c1t2d0s2 - 17678493 - - - - dm schost-103 c2t1d0s2 - 8378640 - - - - dm schost-104 c2t2d0s2 - 17678493 - - - - dm schost-105 c1t3d0s2 - 17678493 - - - - dm schost-106 c2t3d0s2 - 17678493 - - - - v vol01 gen ENABLED 204800 - ACTIVE - - pl vol01-01 vol01 ENABLED 208331 - ACTIVE - - sd schost-101-01 vol01-01 ENABLED 104139 0 - - - sd schost-102-01 vol01-01 ENABLED 104139 0 - - - pl vol01-02 vol01 ENABLED 208331 - ACTIVE - - sd schost-103-01 vol01-02 ENABLED 103680 0 - - - sd schost-104-01 vol01-02 ENABLED 104139 0 - - - pl vol01-03 vol01 ENABLED LOGONLY - ACTIVE - - sd schost-103-02 vol01-03 ENABLED 5 LOG - - - pl vol01-04 vol01 ENABLED 208331 - SNAPDONE - - sd schost-105-01 vol01-04 ENABLED 104139 0 - - - sd schost-106-01 vol01-04 ENABLED 104139 0 - - - [Stop data services, if necessary:] # scswitch -z -g nfs-rg -h ““ [Create a copy of the volume:] # vxassist -g schost-1 snapshot vol01 bkup-vol [Restart data services, if necessary:] # scswitch -z -g nfs-rg -h phys-schost-1 [Verify bkup-vol was created:] # vxprint -g schost-1 TY NAME ASSOC KSTATE LENGTH PLOFFS STATE TUTIL0 PUTIL0 dg schost-1 schost-1 - - - - - - dm schost-101 c1t1d0s2 - 17678493 - - - - ... v bkup-vol gen ENABLED 204800 - ACTIVE - - pl bkup-vol-01 bkup-vol ENABLED 208331 - ACTIVE - - sd schost-105-01 bkup-vol-01 ENABLED 104139 0 - - - sd schost-106-01 bkup-vol-01 ENABLED 104139 0 - - - v vol01 gen ENABLED 204800 - ACTIVE - - pl vol01-01 vol01 ENABLED 208331 - ACTIVE - - sd schost-101-01 vol01-01 ENABLED 104139 0 - - - sd schost-102-01 vol01-01 ENABLED 104139 0 - - - pl vol01-02 vol01 ENABLED 208331 - ACTIVE - - sd schost-103-01 vol01-02 ENABLED 103680 0 - - - sd schost-104-01 vol01-02 ENABLED 104139 0 - - - pl vol01-03 vol01 ENABLED LOGONLY - ACTIVE - - sd schost-103-02 vol01-03 ENABLED 5 LOG - - - [Synchronize the disk group with cluster framework:] # scconf -c -D name=schost-1,sync [Check the file systems:] # fsck -y /dev/vx/rdsk/schost-1/bkup-vol [Copy bkup-vol to the backup device:] # ufsdump 0ucf /dev/rmt/0 /dev/vx/rdsk/schost-1/bkup-vol DUMP: Writing 63 Kilobyte records DUMP: Date of this level 0 dump: Tue Apr 25 16:15:51 2000 DUMP: Date of last level 0 dump: the epoch DUMP: Dumping /dev/vx/dsk/schost-2/bkup-vol to /dev/rmt/0. ... DUMP: DUMP IS DONE [Remove the bkup-volume:] # vxedit -rf rm bkup-vol [Synchronize the disk group:] # scconf -c -D name=schost-1,sync |