topic Re: boot from mirror in Operating System - HP-UX

boot from mirror

AlphaRelease — Mon, 09 Aug 2010 11:19:03 GMT

hi,

hp-ux 11.31: we have a root disk at c0t6d0 that is mirrored with 'vxrootmir' to a disk in c3t6d0. after the mirror was done, as a test, we shut down the system and pulled out the source root disk from c0t6d0. booting did not work! then we pulled out the mirror from c3t6d0 and moved it to c0t6d0. booting now works! as a second test, we now added another disk at c3t6d0 to test disk-replacement. veritas automatically added a diskgroup - the name ends with loopback - but puts the disk in a foreign state. we are not able to initialize that disk (tried 'vxdisksetup -iB c3t6d0 privlen=1024') or import the disk group.

2 questions:
- how to solve the problem
- is there no way to boot from the mirror without physically moving the disk?

best regards and thanks for your time,
fred

Re: boot from mirror

F Verschuren — Mon, 09 Aug 2010 11:23:48 GMT

make sure the disk is bootable:

see (the properly most posted document...)

http://docs.hp.com/en/5991-1236/When_Good_Disks_Go_Bad.pdf

Re: boot from mirror

AlphaRelease — Mon, 09 Aug 2010 11:47:41 GMT

hi 'f verschuren'

thanks for your answer, but it is a veritas managed disk. is your link the right document for veritas volumes?

sorry for my ignorance in this case, but you suggest to make the third/lastly added disk bootable?

thanks

Re: boot from mirror

Torsten. — Mon, 09 Aug 2010 11:57:21 GMT

You obviously belong to the less than 1% of users using vxvm as boot disk ... :-)

Did you mirror the disk with vxvm tools (vxrootmir) or did you just something like a "dd"?

Re: boot from mirror

Torsten. — Mon, 09 Aug 2010 12:00:51 GMT

By the way, if you have an account you should get the software recovery handbook from ITRC and read the vxvm chapter, this will help you.

Re: boot from mirror

AlphaRelease — Mon, 09 Aug 2010 12:05:37 GMT

Hi Torsten,

> You obviously belong to the less than 1% of
> users using vxvm as boot disk ... :-)

I was not aware of this! So are we doing a bad thing here?

> Did you mirror the disk with vxvm tools
> (vxrootmir) or ...

Correct: we used 'vxrootmir -v c3t6d0' to create the mirror.

I found this thread looking like my problem, but not yet tried those actions:

http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=1005490

Best regards,
Frederik

Re: boot from mirror

Torsten. — Mon, 09 Aug 2010 12:12:05 GMT

I'm not this comfortable with vxvm, but IMHO you need to use "-b" while mirroring.

See "man vxrootmir" also.

Re: boot from mirror

AlphaRelease — Mon, 09 Aug 2010 12:59:06 GMT

Thank you Torsten. That must be it. Will try this soon and give you the credits for it if working. How did we miss this! ;)
/BR

Re: boot from mirror

Bill Hassell — Mon, 09 Aug 2010 17:26:12 GMT

>> You obviously belong to the less than 1% of
>> users using vxvm as boot disk ... :-)

> I was not aware of this! So are we doing a bad thing here?

Not a bad thing, just very unusual. LVM is a much simpler method for volume management and most HP-UX systems using VxVM were setup by sysadmins from Sun or other platforms where VxVM was the only viable option. VxVM works but there is a much smaller number of sysadmins that know VxVM. Whether LVM or VxVM, setting up a mirrored boot disk always requires special commands to take care of the boot area.