If you have an existing volume group that you want to recover the structure for before restoring the content, then your can use savevg and restvg

In our site, we have created an exclude file for each volume group so that the files/directories are not backed up, just the Logical Volumes and Filesystem information. For a volume group datavg we have a file called /etc/exclude.datavg that just contains one line:-

Code:

^\./

This can then be used with the following command:-

Code:

savevg -ef /disaster/datavg.structure datavg

What this is doing is saving the volume group, but excluding everything it finds that matches the pattern in the file. The pattern we have picked means it excludes everything, so you just get the structure, for which the definitions are a few small files. The directory /disaster needs to be in the root volume group, but not necessarily in the root filesystem. It just needs to be somewhere that will be included on your mksysb media.

Be sure to remove the directory /tmp/vgdata before you start and create your mksysb afterwards. Of course you can use whatever file name you like to save the information. You can copy that to another server that is already running and use it if you wish. You may need to be aware of conflicting logical volumes or filesystems in this case.

After restoring your mksysb elsewhere, you can use the following to build your volume group:-

Code:

restvg -q -f /disaster/datavg.structure hdiskx hdisky hdiskz

You need to give it enough disks to build what you had before.

I used to script this up with a mklv then a crfs using the LV I'd just built and on some servers it could take 90 minutes to run the script. When we got wise and used restvg it was about 10 minutes and the filesystems were all prepared, added to /etc/filesystems and mounted ready for data restore.


It is such a joy to recover with such ease and it emphasises to me why AIX is an excellent OS choice.



I hope that this helps. Let me know if I've not made anything clear.

Robin
Liverpool/Blackburn
UK