primary boot disk on mirrored system disks

[Joe Profaizer]

How can I tell which disk is the primary boot disk. Both disks are mirrored system disks and the system is up and running. I'm not sure if lvlnboot -v lists the primary disk first or if it just lists them in alpha order. Below is my display.
# lvlnboot -v
Boot Definitions for Volume Group /dev/vg00:
Physical Volumes belonging in Root Volume Group:
/dev/dsk/c1t2d0 (0/0/1/1.2.0) -- Boot Disk
/dev/dsk/c2t2d0 (0/0/2/0.2.0) -- Boot Disk
Boot: lvol1 on: /dev/dsk/c1t2d0
/dev/dsk/c2t2d0
Root: lvol3 on: /dev/dsk/c1t2d0
/dev/dsk/c2t2d0
Swap: lvol2 on: /dev/dsk/c1t2d0
/dev/dsk/c2t2d0
Dump: lvol2 on: /dev/dsk/c1t2d0, 0

I want to reboot my system and pull out the secondary disk so I can apply patches to the primary disk and have the secondary disk to fall back on if the patch installation goes sour.

Thanks,

.>Joe

[harry d brown jr]

You DON'T need to YANK out the disks, just SPLIT the mirror and then do your patching. PLUS make sure you get TWO make_tape_recovery's before doing anything!

live free or die
harry

[PIYUSH D. PATEL]

Hi,

/dev/dsk/c1t2d0 is your primary disk.

You can also check by booting the system and checking the primary path...if you want to be doubly sure.

lvdisplay -v /dev/vg00/lvol3 and in the output the first disk which you see is the primary disk.

Be sure to boot the system in the single user mode or -lm -lq mode to prevent getting errors after removing the second disk.

You can even split the mirror and apply the patches.

Piyush

[Sanjay_6]

Hi Joe,

vgdisplay and lvdisplay will tell you which disk is configured as primary and which one is seconday. in the lvlnboot -v /dev/vg00 the first disk is normally the primary disk.

To find out which disk you had booted from, try

echo 'boot_string/S'|adb /stand/vmunix /dev/mem

Hope this helps.

regds

[James R. Ferguson]

Hi Joe:

'lvlnboot -v' lists the primary disk first. Another way to ascertain is to do 'lvdisplay -v /dev/vgXX/lvolX' and look at the disk under the PV1 and PV2 columns. "PV1" is the primary.

Instead of physically pulling disks, you could 'vgsplit' the mirror, or you could simply have a current Ignite recovery tape handy in the event of problems.

Regards!

...JRF...

[S.K. Chan]

Like others have mentioned "lvlnboot -v" lists the primary disk first. This is a bit of an unusual practice. Are you planning to do this everytime you install patches ? If you do why bother have your root disk mirror with Mirror/UX, you would be better off creating a duplicate root disk manually without Mirror/UX and use that as your backup root disk, synchronize them when you make changes to the primary root disk but that's not the point. The combination of "lvsplit" and "lvmerge" should work out for you but if I were you I would do 3 things ..
1) Make sure all dependencies of the patches you're installing are covered, that way the success rate is higher.
2) Make sure ignite tape recovery is done first.
3) If you can afford it make a 3rd root disk duplicate manually (not using Mirror/UX), attached is the process.
..just my thought ..

[MANOJ SRIVASTAVA]

Hi Joe

c1t2d0 is the primary disk ,in case the patches need a reboot then it will be better that you split the mirror , relaod the patches and then check whether the system boots fine ,


Manoj Srivastava

[Noel Miranda_1]

after lvlnboot -v give the setboot command