4) Parting the proxy groups
Once synchronization copying is completed, the master group and the proxy group become synchronized. Snapshots of a master group can be collected in a proxy group by parting the synchronized master group and proxy group.
4-1) Secure consistency of the file systems.
To secure consistency of snapshot file systems, restrain update of the file systems. However, file systems such as /, /usr, and /var are necessary for the system to operate, they cannot be unmounted during system operation. You can follow the procedure as below in order to reduce write occurrences to system disks and write occurrences to system disks that are not updated yet.
Boot the system in single user mode. (This can be skipped.)
Exit all active application programs writing in the system disks. (This can be skipped.)
Execute the sync(1) command to write file system data updated in memory but not yet written to the disks.
Even if all the steps a., b., and c. are enforced, it is impossible to completely restrain update on the file system. As a result, inconsistency similar to that after a system panic might occur in a snapshot file system.
If a., b., and c. are all enforced, a snapshot file system will be similar to a file system after a panic occurs in single user mode.
If only c. is enforced skipping a. and b., a snapshot file system will be similar to a file system after a panic occurs during the system operation.
In any of these situations, a file system may have inconsistency, and the file system should be checked for consistency and repaired as described in step 5-2).
4-2) When the system was started in single user mode in a. of step 4-1), start the GDS services.
# /usr/bin/systemctl start fjsvsdx.service |
4-3) Part the proxy groups.
# sdxproxy Part -c System -p Proxy1,Proxy2 |
See
When using GDS Management View, see "Part" in "7.8.1.2 Operation Procedure."
4-4) When the system was booted in single user mode in a. of step 4-1), reboot it in multi-user mode.
4-5) When application programs were exited in b. of step 4-1), launch the application programs.
5) Configuring an alternative boot environment
Enable the system to boot from the proxy volumes in preparation for an error due to a failed system disk or damaged data.
5-1) Set the access mode attribute of the proxy volumes to rw (read and write).
If the access mode attribute of proxy volumes created in the proxy group is ro (read only), it must be changed to rw (read and write). The access mode attribute can be viewed in the MODE field output by the sdxinfo -V -e long command. If the access mode attribute is already set to rw (read and write), executing the following commands is not necessary.
# sdxvolume -F -c System -v Proot,Pboot,Pefi,Pswap,Pvar,Pusr # sdxattr -V -c System -v Proot -a mode=rw # sdxattr -V -c System -v Pboot -a mode=rw # sdxattr -V -c System -v Pefi -a mode=rw # sdxattr -V -c System -v Pswap -a mode=rw # sdxattr -V -c System -v Pvar -a mode=rw # sdxattr -V -c System -v Pusr -a mode=rw |
5-2) Verify and repair the file systems on the proxy volumes.
There may be inconsistency in file systems on proxy volumes, and so verify and repair them using the fsck(8) command. If the file system type is xfs, use xfs_repair(8) instead of fsck(8).
# sdxvolume -N -c System -v Proot,Pboot,Pefi,Pswap,Pvar,Pusr # fsck /dev/sfdsk/System/dsk/Proot # fsck /dev/sfdsk/System/dsk/Pboot # fsck /dev/sfdsk/System/dsk/Pefi # fsck /dev/sfdsk/System/dsk/Pvar # fsck /dev/sfdsk/System/dsk/Pusr |
5-3) Configure the alternative boot environment.
# sdxproxy Root -c System -p Proxy1,Proxy2 |
Once the alternative boot environment is configured, the following message is output.
SDX:sdxproxy: INFO: completed definitions of alternative boot environment: current-boot-device=Root1 Root2 alternative-boot-device=Proot1 Proot2 |
Be sure to keep a copy of the output boot device names in the current boot environment (current-boot-device values) and in the alternative boot environment (alternative-boot-device values).
5-4) Stop the proxy volumes.
To protect data in the alternative boot environment from illegal write access, the proxy volumes should be inactivated.
# sdxvolume -F -c System -v Proot,Pboot,Pefi,Pswap,Pvar,Pusr |
Information
When using GDS Management View, select a proxy volume and execute [Operation]:[Stop Volume] in the Main Screen.
6) Verifying the alternative boot environment (This can be skipped.)
Confirm that the system can be booted in the alternative boot environment.
6-1) Boot the system through the alternative boot environment.
From boot devices displayed in the EFI boot manager's boot option selection screen, select one of the devices in the alternative boot environment output in the message as shown in step 5-3).
Root1 Root2 Proot1 <- Select Proot2 |
6-2) When the system is started in single user mode, restart it in multi-user mode.
If the system was started in single user mode in a. of step 4-1), the alternative boot environment is started in single user mode. In this case, after changing the settings to start the alternative boot environment in multi-user mode, stop the system. Then, execute step 6-1) again. For the settings to start in multi-user mode, see "A.10 Changing system run level."
6-3) Confirm that it was booted normally.
Using the mount(8) command or the sdxinfo command, make sure that it was booted normally in the alternative boot environment and that GDS objects do not contain errors. Additionally, according to need, you should confirm that file system contents in the alternative boot environment are correct and that applications can normally run.
6-4) Return to the original boot environment.
From boot devices displayed in the EFI boot manager's boot option selection screen, select one of the devices in the alternative boot environment output in the message as shown in step 5-3).
Root1 <- Select Root2 Proot1 Proot2 |
6-5) Stop the proxy volumes.
To protect data in the alternative boot environment from illegal write access, the proxy volumes should be inactivated.
# sdxvolume -F -c System -v Proot,Pboot,Pefi,Pswap,Pvar,Pusr |
Information
When using GDS Management View, select a proxy volume and execute [Operation]:[Stop Volume] in the Main Screen.
7) Rejoining the proxy groups
To back up the system disks again, copy contents in the system disks to the backup disks again by rejoining a group of the backup disks (proxy group) to a group of the system disks (master group).
Note
Copying by rejoining is finished quickly since only the updated blocks in the master and the proxy are copied through the just resynchronization mechanism (JRM). However, if the system is rebooted after the proxy is parted, the JRM is disabled and the entire volumes will be copied when the proxy is rejoined. Therefore, copying of the entire volumes is conducted instead of just resynchronization when the proxy groups are rejoined in step 7-1) if the system is rebooted after step 4-4) or step 6).
7-1) Rejoin the proxy groups.
# sdxproxy Rejoin -c System -p Proxy1,Proxy2 |
See
When using GDS Management View, see "Rejoin" in "7.8.1.2 Operation Procedure."
7-2) Confirm that synchronization copying is complete.
# sdxinfo -S -c System
OBJ CLASS GROUP DISK VOLUME STATUS
------ ------- ------- ------- ------- --------
slice System Group1 Root1 root ACTIVE
slice System Group1 Root2 root ACTIVE
slice System Group1 Root1 boot ACTIVE
slice System Group1 Root2 boot ACTIVE
slice System Group1 Root1 efi ACTIVE
slice System Group1 Root2 efi ACTIVE
slice System Group2 Var1 swap ACTIVE
slice System Group2 Var2 swap ACTIVE
slice System Group2 Var1 var ACTIVE
slice System Group2 Var2 var ACTIVE
slice System Group2 Var1 usr ACTIVE
slice System Group2 Var2 usr ACTIVE
slice System Proxy1 Proot1 Proot STOP
slice System Proxy1 Proot2 Proot STOP
slice System Proxy1 Proot1 Pboot STOP
slice System Proxy1 Proot2 Pboot STOP
slice System Proxy1 Proot1 Pefi COPY
slice System Proxy1 Proot2 Pefi COPY
slice System Proxy2 Pvar1 Pswap STOP
slice System Proxy2 Pvar2 Pswap STOP
slice System Proxy2 Pvar1 Pvar COPY
slice System Proxy2 Pvar2 Pvar COPY
slice System Proxy2 Pvar1 Pusr COPY
slice System Proxy2 Pvar2 Pusr COPY |
If synchronization copying is in process, COPY is displayed in the STATUS field for slices of the copy destination proxy group. If the STATUS of every slice in the proxy group is STOP, the synchronization copying is completed.
Information
On the GDS Management View main screen, slices composing proxy volumes are indicated as below.
If synchronization copying is in process, the status is "copy" and the icon color is blue.
After synchronization copying is completed, the status is "stop" and the icon color is black.
7-3) Part the proxy groups, configure the alternative boot environment, and confirm that the alternative boot environment is valid following the step from 4) to 6).
