Just last week I received a new IBM pSeries 550! I admit, my first time setting this thing up was a bit frustrating. We did not have any Hardware Management Console (HCM), but through trial and error I was able to get into the console by using a null modem cable and HyperTerminal on a Windows laptop. There are some peculair details regarding the initial setup of the machine, but focusing on disk mirroring I will leave those out for now.
Once the machine was configured and brought on the network. The first thing to do was configure disk mirroring. This is a policy we have in place for all production machines. Drives do fail!! Disk mirroring on AIX, atleast with version 6.1, is pretty easy and straight forward. A lot less commands to type than when disk mirroring with Solaris default software!!
Display volume group information
Since we already have a, Root Volume Group “rootvg”
# lsvg -p rootvg
rootvg:
PV_NAME PV STATE TOTAL PPs FREE PPs FREE DISTRIBUTION
hdisk0 active 546 488 109..74..87..109..109
for our mirror, all we need to do is extend it onto the second disk “hdisk1”. The first disk is “hdisk0”.
# extendvg rootvg hdisk1
0516-1254 extendvg: Changing the PVID in the ODM.
Checking the rootvg again, we see now that there are two disks on this volume group:
# lsvg -p rootvg
rootvg:
PV_NAME PV STATE TOTAL PPs FREE PPs FREE DISTRIBUTION
hdisk0 active 546 488 109..74..87..109..109
hdisk1 active 546 546 110..109..109..109..109
Start Mirroring Process
Now that the rootvg is written to the second disk, we can go ahead and start the mirroring process on the second disk, “hdisk1”.
# mirrorvg rootvg hdisk1
0516-1804 chvg: The quorum change takes effect immediately.
0516-1126 mirrorvg: rootvg successfully mirrored, user should perform
bosboot of system to initialize boot records. Then, user must modify
bootlist to include: hdisk0 hdisk1.
Taking heed to the message displayed from the completion of “mirrorvg”:
# bosboot -ad /dev/hdisk1
bosboot: Boot image is 36835 512 byte blocks.
With “bosboot” we are saying copy the byte blocks from the first disk “hdisk0” necessary to boot from the second disk “hdisk1” should the first drive fail. Looking at the current boot list we just see the first drive:
# bootlist -m normal -o
hdisk0 blv=hd5
The following command configures our boot order to include the second drive after the first:
# bootlist -m normal hdisk0 hdisk1
Verifying we see:
# bootlist -m normal -o
hdisk0 blv=hd5
hdisk1 blv=hd5
Good post. Before you extend the vg it’s a good idea to do an lspv to see your current disk status. Usually right out of the box hdisk1 will not be in use:
# lspv
hdisk0 00f6896363c5a76a rootvg active
hdisk1 none None
#
Nice post!
http://geekswing.com/geek/how-to-mirror-your-root-disk-on-aix-aka-rootvg/
Ben, you are right. I should have three that in there. 🙂 Nevertheless, thanks for your suggestion.