Solaris

just read my last post. this IS my answer... and yes, i've done that a thousend times! you CAN unmirror the disks to have a backup of the system but you don't need to!

Thanks for the reply.

yes we need to unmirror to have a backup of the system.

I do know how to unmirror the root filesystem, but I have some doubts that what all steps we should leave from the un-mirroring procedure, as we have to re-mirror the root disks again after patching.

Also will the unmirror steps be same for root and /opt,/usr etc. ?


Thanks,
Kamal.

As I have already said, no you do not need to break the mirrors in order to patch the system, just as you would not break the mirrors to add a new user account or add a new mount.

If you have an off line back from which you can restore the system quickly enough then breaking the mirrors just makes the whole process a lot longer.

If you wish to break the mirrors using metdetach(1m) then you run:

Code:

# metadetach mirror submirror

In your case:

Code:

# metadetach d0 d20

The /etc/vfstab inside d20 will need amending to make it mount the actual device that is in d20 (i.e. /dev/dsk/c1t1d0s0 ) and when booting off it you will need to boot off the dev-alias in the OBP that points to that disk, if you are wanting to use the broken off sub-mirror to recover back to the state the machine was in before mirroring make sure you can boot off it before patching the other side of the mirror.

Absolutely sure. No need to unmirror. However, I like to use live update to keep the down time at a minimum and to allow me to quickly and easily go back if the patches end up breaking something on my systems. If you haven't done it before, it may be a bit of a learning curve; but, once you've done it, it is so easy and nice. See BigAdmin Sun Docs: How To Use Solaris Live Upgrade to Install Patches and check out the documentation at Upgrading With Solaris Live Upgrade (Solaris 10 5/09 Installation Guide: Solaris Live Upgrade and Upgrade Planning) - Sun Microsystems.

I can apply a patch cluster in the middle of the day without affecting my users at all. Then just after the end of the day, I can activate the patched environment and reboot. Total downtime just a few minutes.

Hi kamaldeep1986,
if I got your question true,question is do you need to unmirror your disks in case system patching. Absolutely "no". Suns patches upgrading enough often, you would not unmirror your disks every time when u need patch your system :)

thank you all, for your help.

We have performed the patching successfully.