Edit: Still good to know.
Originally posted April 14, 2020 on AIXchange
What to do when your AIX system has an altinst_rootvg.
Awhile back this interesting question came up: If you’re using alt disk to clone and upgrade your AIX system and later on you log into that system and see it has an altinst_rootvg, how do you determine the AIX version that’s on the inactive disk? What if you want to look at old data or information on that disk?
The answer is explained here:
Test2:/# oslevel -s
7100-01-04-1141
Test2:/#
Test2:/# lspv
hdisk0 00d342e7131c6b47 rootvg active
hdisk1 00d342d637j21a59 altinst_rootvg
Test2:/#
Test2:/# alt_rootvg_op -W -d hdisk1
Waking up altinst_rootvg volume group …
Test2:/#
Now the altinst_rootvg is in Active state also alt filesystems are in mounted state on the server
Test2:/# lspv
hdisk0 00d342e7131c6b47 rootvg active
hdisk1 00d342d637j21a59 altinst_rootvg active
Test2:/#
Test2:/# df
Filesystem 512-blocks Free %Used Iused %Iused Mounted on
/dev/hd4 524288 380024 28% 3091 3% /
/dev/hd2 3801088 396856 90% 34020 8% /usr
/dev/hd9var 2621440 2279336 14% 3560 2% /var
/dev/hd3 524288 499272 5% 105 1% /tmp
/dev/hd1 524288 507336 4% 102 1% /home
/proc – – – – – /proc
/dev/hd10opt 524288 278872 47% 3370 6% /opt
/dev/alt_hd4 524288 365552 31% 3871 3% /alt_inst
/dev/alt_hd1 524288 507336 4% 104 1% /alt_inst/home
/dev/alt_hd10opt 1310720 562888 58% 5694 4% /alt_inst/opt
/dev/alt_hd3 524288 499120 5% 116 1% /alt_inst/tmp
/dev/alt_hd2 5636096 184120 97% 103336 15% /alt_inst/usr
/dev/alt_hd9var 2621440 1835656 30% 6632 3% /alt_inst/var
We need to start the chroot shell within the alternate rootvg to identify the OS level/TL/SP information.
Test2:/# chroot /alt_inst /usr/bin/ksh
Test2:/# oslevel -s
7100-01-01-1216
Test2:/#
Test2:/# exit
You can return to the rootvg environment by exit from the alt shell.
Now it is really really important to put the cloned rootvg back to sleep.
Test2:/# alt_rootvg_op -S altinst_rootvg
Putting volume group altinst_rootvg to sleep …
forced unmount of /alt_inst/var
forced unmount of /alt_inst/usr
forced unmount of /alt_inst/tmp
forced unmount of /alt_inst/opt
forced unmount of /alt_inst/home
forced unmount of /alt_inst
Fixing LV control blocks…
Fixing file system superblocks…
Related: The IBM Knowledge Center explains how to access data between the original rootvg and the new alternate disk and provides this intro to the alt_rootvg_op command. And in an AIXchange post from August 2019, I shared Chris Gibson’s tips on managing multiple instances of alt_rootvg.