IBM SG24-5131-00 User Manual

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IBM Certification Study Guide  AIX HACMP
9. After the backup is complete and verified, unmount and delete the new file 
system and the logical volume you used for it.
10.Use the 
mklvcopy
 command to add back the logical volume copy you 
previously split off to the fslv logical volume.
11.Resynchronize the logical volume.
Once the mirror copy has been recreated on the logical volume, the 
syncvg
 
command will resynchronize all physical partitions in the new copy, including 
any updates that have occurred on the original copy during the backup 
process.
It is always a good idea to check a backup for validity.
8.7.2  Using Events to Schedule a Backup
As described above, a 
crontab
 entry is often used for scheduling nightly 
backups during off-peak hours of the application. Now as you have several 
cluster nodes, each of them would need a 
crontab
 entry, in order to get its 
own data backed up. This 
crontab
 entry can determine whether only the 
“normal” data is backed up, i.e. the data this cluster node cares about during 
“normal” operations, or, in case of another’s node failure and a subsequent 
takeover of this node’s resources, backing up both of the cluster nodes’ data.
Whenever one node takes over the reources of another node, the 
node_down_remote event has happened. You can use a post-event to the 
node_down_remote event to change the 
crontab
 entry from backing up only 
the local node’s data into backing up both nodes’ data. 
Furthermore, if the second node eventually comes up again and takes its 
resources back, you will see a 
node_up_remote event in your logs. Thus, you 
can configure a post-event to the 
node_up_remote event to change the 
crontab entry back to the “normal” setting. 
If you want to do a split-mirror backup, the crontab entry has to invoke a 
script, implementing the steps described above.
A more detailed description of this procedure can be found in the redbook 
HACMP/6000 Customization Examples, SG24-4498, Chapter 6.
8.8  User Management
As 2.7, “User ID Planning” on page 48 described, on an HACMP cluster, the 
administrator has to take care of user and group IDs throughout the cluster. If