| PRIMECLUSTER Global Disk Services Configuration and Administration Guide 4.2 (Linux) |
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Contents
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| Chapter 6 Backing Up and Restoring | > 6.6 Backing Up and Restoring through an External Server | > 6.6.1 Backing Up and Restoring a Logical Volume with No Replication |
2) Stopping the services
Exit all applications accessing the application volume Volume1 in the primary domain on Node1 and Node2.
When Volume1 is used as a file system, it should be unmounted.
3) Stopping the application volume
To write-lock volume Volume1, inactivate Volume1 on Node1 and Node2 in the primary domain. Execute the following command on Node1 or Node2.
# sdxvolume -F -c Class1 -v Volume1 -e allnodes |
4) Viewing the configuration of the application volume
On Node1 or Node2 in the primary domain, view the configuration of application volume Volume1 that is the backup target.
# sdxinfo -c Class1 OBJ NAME TYPE SCOPE SPARE ------ ------- -------- ----------- ----- class Class1 shared Node1:Node2 0 OBJ NAME TYPE CLASS GROUP DEVNAM DEVBLKS DEVCONNECT STATUS ------ ------- ------ ------- ------- ------- -------- ---------------- ------- disk Disk1 stripe Class1 Group1 sda 8380800 Node1:Node2 ENABLE disk Disk2 stripe Class1 Group1 sdb 8380800 Node1:Node2 ENABLE disk Disk3 stripe Class1 Group1 sdc 8380800 Node1:Node2 ENABLE disk Disk4 stripe Class1 Group1 sdd 8380800 Node1:Node2 ENABLE OBJ NAME CLASS DISKS BLKS FREEBLKS SPARE ------ ------- ------- ------------------------ --------- -------- ----- group Group1 Class1 Disk1:Disk2:Disk3:Disk4 32964608 31850496 * OBJ NAME CLASS GROUP SKIP JRM 1STBLK LASTBLK BLOCKS STATUS ------ ------- ------- ------- ---- --- -------- -------- -------- -------- volume * Class1 Group1 * * 0 65535 65536 PRIVATE volume Volume1 Class1 Group1 * * 65536 1114111 1048576 STOP volume * Class1 Group1 * * 1114112 32964607 31850496 FREE OBJ CLASS GROUP DISK VOLUME STATUS ------ ------- ------- ------- ------- -------- slice Class1 Group1 * Volume1 STOP |
If application volume Volume1 belongs to a stripe group, also pay attention to the stripe width.
# sdxinfo -G -c Class1 -o Group1 -e long OBJ NAME CLASS DISKS BLKS FREEBLKS SPARE MASTER TYPE WIDTH ------ ------- ------- ----------------------- -------- -------- ----- ------ ------ ----- group Group1 Class1 Disk1:Disk2:Disk3:Disk4 32964608 31850496 * * stripe 256 |
5) Creating a shadow volume for backup
On backup server Node3, create a backup volume (shadow volume) in the same configuration as the application volume found in step 4). The following settings are necessary on backup server Node3.
Application volume data may be damaged if data is written into a shadow volume in incorrect configuration. Be sure to confirm that the shadow volume configuration is correct in step 5-4).
5-1) Registering shadow disks
Register disks sda, sdb, sdc, and sdd with shadow class Class2, and name them Disk1, Disk2, Disk3, and Disk4 respectively.
# sdxshadowdisk -M -c Class2 -d sda=Disk1,sdb=Disk2,sdc=Disk3,sdd=Disk4 |
The disk names must correspond to the disk names assigned in step 1-1). The disk names assigned in 1-1) can be viewed in the NAME field for disk information displayed with the sdxinfo command in step 4).
The class can be assigned any name.
5-2) Creating a shadow group
Connect shadow disks Disk1, Disk2, Disk3, and Disk4 to stripe type shadow group Group1.
# sdxshadowdisk -C -c Class2 -g Group1 -d Disk1,Disk2,Disk3,Disk4 -a type=stripe,width=256 |
If the application volume belongs to a stripe group or a concatenation group, the order of connecting shadow disks to a shadow group must correspond to the order of connecting disks to a group in step 1-2). The order of connecting disks in step 1-2) can be viewed in the DISKS field for group information displayed with the sdxinfo command in step 4).
When the application volume belongs to a stripe group, the stripe width of a shadow group must correspond to the stripe width specified in step 1-2). The stripe width specified in step 1-2) can be viewed in the WIDTH field for group information displayed with the sdxinfo -e long command in step 4).
The group can be assigned any name.
5-3) Create a shadow volume.
Create shadow volume Volume1 to shadow group Group1.
# sdxshadowvolume -M -c Class2 -g Group1 -v Volume1 -s 1048576 |
The volume must be created in the size corresponding to the volume size in step 1-3). The size of a volume created in step 1-3) can be viewed in the BLOCKS field for volume information displayed with the sdxinfo command in step 4).
If there are multiple volumes, the corresponding shadow volumes must be created in the order of ascending values (first block numbers) in the 1STBLK field for volume information displayed with the sdxinfo command in step 4).
The volume can be assigned any name.
5-4) Viewing the shadow volume configuration
Using the sdxinfo command, confirm that the group configuration and the volume configuration are correct based on group information in the DISKS field, volume information in the 1STBLK field and in the BLOCKS field and so on.
# sdxinfo -c Class2 OBJ NAME TYPE SCOPE SPARE ------ ------- -------- ----------- ----- class Class2 local Node3 0 OBJ NAME TYPE CLASS GROUP DEVNAM DEVBLKS DEVCONNECT STATUS ------ ------- ------ ------- ------- ------- -------- ------------- ------- disk Disk1 stripe Class2 Group1 sda 8380800 Node3 ENABLE disk Disk2 stripe Class2 Group1 sdb 8380800 Node3 ENABLE disk Disk3 stripe Class2 Group1 sdc 8380800 Node3 ENABLE disk Disk4 stripe Class2 Group1 sdd 8380800 Node3 ENABLE OBJ NAME CLASS DISKS BLKS FREEBLKS SPARE ------ ------- ------- ------------------------ -------- -------- ----- group Group1 Class2 Disk1:Disk2:Disk3:Disk4 32964608 31850496 * OBJ NAME CLASS GROUP SKIP JRM 1STBLK LASTBLK BLOCKS STATUS ------ ------- ------- ------- ---- --- -------- -------- -------- -------- volume * Class2 Group1 * * 0 65535 65536 PRIVATE volume Volume1 Class2 Group1 * * 65536 1114111 1048576 ACTIVE volume * Class2 Group1 * * 1114112 32964607 31850496 FREE OBJ CLASS GROUP DISK VOLUME STATUS ------ ------- ------- ------- ------- -------- slice Class2 Group1 * Volume1 ACTIVE |
For a stripe volume, see also the stripe width.
# sdxinfo -G -c Class2 -o Group1 -e long OBJ NAME CLASS DISKS BLKS FREEBLKS SPARE MASTER TYPE WIDTH ------ ------- ------- ----------------------- -------- -------- ----- ------ ------ ----- group Group1 Class2 Disk1:Disk2:Disk3:Disk4 32964608 31850496 * * stripe 256 |
6) Backing up to tape
On backup server Node3, back up data from the shadow volume to tape. In the following examples, back up data in shadow volume Volume1 to a tape medium of tape device /dev/st0.
For details on the backup method, see the manuals of file systems to be backed up and used commands.
In a GFS Shared File System
Back up through the method as described in step 6a).
6a) When backing up data with the dd(1) command
# dd if=/dev/sfdsk/Class2/dsk/Volume1 of=/dev/st0 bs=32768 |
6b) When backing up the ext3 file system with the tar(1) command
6b-1) Mount the ext3 file system on shadow volume Volume1 on /mnt1, a temporary mount point, in read only mode.
# mkdir /mnt1 # mount -t ext3 -o ro /dev/sfdsk/Class2/dsk/Volume1 /mnt1 |
6b-2) Back up data held in the file system to tape.
# cd /mnt1 # tar cvf /dev/st0 . |
6b-3) Unmount the file system mounted in step 6b-1).
# cd / # umount /mnt1 # rmdir /mnt1 |
7) Removing the shadow volume
After the backup process is complete, remove the shadow volume to prevent improper access to it. The following procedure must be performed on backup server Node3.
7-1) Stopping the shadow volume
Stop shadow volume Volume1.
# sdxshadowvolume -F -c Class2 -v Volume1 |
7-2) Removing the shadow volume
Remove shadow volume Volume1.
# sdxshadowvolume -R -c Class2 -v Volume1 |
7-3) Removing the shadow group
Remove shadow group Group1.
# sdxshadowgroup -R -c Class2 -g Group1 |
7-4) Removing the shadow disks
Remove shadow disks Disk1, Disk2, Disk3, and Disk4.
# sdxshadowdisk -R -c Class2 -d Disk1 # sdxshadowdisk -R -c Class2 -d Disk2 # sdxshadowdisk -R -c Class2 -d Disk3 # sdxshadowdisk -R -c Class2 -d Disk4 |
8) Resuming the services
Resume the services in the primary domain. The following procedure must be performed on the node that runs the services.
8-1) Activating the application volume
Activate application volume Volume1.
# sdxvolume -N -c Class1 -v Volume1 |
8-2) Resuming the services
When the file system on application volume Volume1 was unmounted in step 2), mount it again.
Start the applications using Volume1.
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