topic Re: Boot disk in Operating System - HP-UX

Boot disk

John Guster — Sat, 22 Sep 2007 11:26:16 GMT

Here is the case:
vg00 has 7 lvols on disk A. The mirroring disk B only has lvol1, 2, and 3 for /stand, swap, and / . Rest lvols have not mirrored yet to disk B. Will the system boot from disk B at this point?
Any idea?

Re: Boot disk

James R. Ferguson — Sat, 22 Sep 2007 12:23:37 GMT

Hi John:

Yes, assuming that the second disk was correctly 'pvcreate'd; and s 'mkboot' done for it; and assuming that the first three logical volumes were mirrored in their ordinal sequence.

Of course, you need to mirror your remaining logical volumes too. After all, a mirror of vg00 without anything more than '/stand' and the root filesystem doesn't gain you much more than single user mode. It could be likened to having a head without a body.

Regards!

...JRF...

Re: Boot disk

John Guster — Sat, 22 Sep 2007 12:53:59 GMT

I can not recall when the mirror disk is activated during booting process. Will this booting bring system up to init 3, instead of single user mode? Thanks for your response.

Re: Boot disk

James R. Ferguson — Sat, 22 Sep 2007 13:03:44 GMT

Hi (again) John:

> Will this booting bring system up to init 3, instead of single user mode?

The run level is set in '/etc/inittab'. Since '/etc' and '/sbin' are only directories beneath '/' the system will attempt to run all of the startup scripts in '/sbin/init.d' through run-level 3 if you don't specifically boot into single-user mode. Failures in some of the scripts are certain, since the mounting (at run-level 1) of the missing filesystems for the missing logical volumes will fail.

Regards!

...JRF...

Re: Boot disk

John Guster — Sat, 22 Sep 2007 13:48:44 GMT

lvmrc activates vg00 during booting process. as long as vg00 is activated, all lvols are avaliable for mounting regardingless if the lvol is mirrored or not. In this case the system should be brought up to default run level 3 with all file systems defined in /etc/fstab mounted. I don't see why it would fail due to lvols not on booting disk.

Re: Boot disk

James R. Ferguson — Sat, 22 Sep 2007 14:49:09 GMT

Hi (again) John:

> lvmrc activates vg00 during booting process. as long as vg00 is activated, all lvols are avaliable for mounting regardingless if the lvol is mirrored or not. In this case the system should be brought up to default run level 3 with all file systems defined in /etc/fstab mounted. I don't see why it would fail due to lvols not on booting disk.

Yes, all of the above are true. My original answers were predicted on the assumption that you were booting from a disk with *only* lvol1-3 as in after a failure of the primary disk. In that case, why mirror? In fact, what are you trying to accomplish, or is this solely an academic question? I presume that you want a useful server, not just one that boots.

Regards!

...JRF...

Re: Boot disk

John Guster — Sat, 22 Sep 2007 15:00:08 GMT

I have a messy system. Need bring it down to replace tape drive. It is kind of no ignite image because of bad tape drive. Once tape drive is replaced, we will reignite the system, make it up right.
Thank you for your inputs.

Re: Boot disk

John Guster — Sat, 22 Sep 2007 15:00:53 GMT

thanks for prompt discussion.