topic Re: maintenance mode in Operating System - HP-UX

maintenance mode

Lalo_Weng — Mon, 19 Nov 2001 07:43:13 GMT

Hi, I heard that there's a maintenance mode in hp-ux. As I understand that single user mode means that other user can't log in system except root. But I only know maintenance mode by name. Could any one tell me more about that? Under which circumstance, will we startup the system in maintenance mode? Why maintenance mode? Or could you give me a link for this topic?

Thanks in advance.

Re: maintenance mode

Bill McNAMARA_1 — Mon, 19 Nov 2001 07:54:01 GMT

hpux -lm

no vg's are active. It's more or less lvm maintenance mode.

you got / /stand and swap active.

You'd typically boot that way wheren there's an lvm prob such as /etc/lvmtab or the pvra (pvcreate) or VGRA (vgcreate) on the disk.

Later,
Bill

Re: maintenance mode

G. Vrijhoeven — Mon, 19 Nov 2001 08:04:23 GMT

Hi,

I agree with Bill and i like to add:

bo pri -lq

this is a boot option that overrides the quorum loss. ( 50% + 1 disk of the volume groups must be available to boot lvm)

Gideon

Re: maintenance mode

Vincent Farrugia — Mon, 19 Nov 2001 08:09:50 GMT

Hello,

Maintenance mode provides a means to boot from an LVM disk without the LVM data structures. This is helpful when LVM data structures have been lost. It is invoked by typing:

hpux -lm

at the ISL prompt.

Bill's answer is correct as well (he teaches the subject, so he must know!)

HTH,
Vince

Re: maintenance mode

Lalo_Weng — Mon, 19 Nov 2001 08:16:55 GMT

Hi, Thanks for all reply, But I don't understand thoroughly for Vincent input 'boot from an LVM disk without the LVM data structures', Could you elaborate on it?

Thanks a lot!

Re: maintenance mode

Vincent Farrugia — Mon, 19 Nov 2001 08:37:54 GMT

Hi,

It means that no volume groups are activated. It uses a known offset to find start of lvol1. No primary swap, dump or LVM are set when booted to access the root file system.

It is important to reboot afterwards.

HTH,
Vince

Re: maintenance mode

Lalo_Weng — Mon, 19 Nov 2001 08:58:50 GMT

but, what is the difference between maintenance mode and singe user mode?

Thanks.

Re: maintenance mode

Vincent Farrugia — Mon, 19 Nov 2001 09:17:32 GMT

Hi,

In maintenance mode, the system boots even if the LVM boot disk is unbootable, since it bypasses the BDRA and LABEL file. However, in single-user mode, the boot disk must be bootable. So use maintenance mode if the disk is not bootable.

HTH,
Vince

Re: maintenance mode

Vincent Farrugia — Mon, 19 Nov 2001 09:24:15 GMT

More info:

In single-user mode, vg00 is activated and the root and /stand are mounted. If these cannot be activated and mounted due to a variety of issues, maintenance mode provides you with a solution. It does not activate or mount anything.

HTH,
Vince

Re: maintenance mode

Lalo_Weng — Mon, 19 Nov 2001 09:39:19 GMT

Hi, Vincent, Thanks a lot for your input. Here I have another point need your confirmation.
That is: If the LIF header area or LIF volumn area is corrupt, then We can't boot the system no matter in which mode, right?

Re: maintenance mode

Vincent Farrugia — Mon, 19 Nov 2001 09:51:57 GMT

Hello,

When LIF is corrupted, you have to rebuild it using either Recovery media, afterwards rebooting to maintenance mode to update the BDRA and LABEL files using lvlnboot command. You can also boot an ignite tape to restore everything at once.

One thing I failed to tell is that booting in maintenance mode fails if the BDRA is corrupted. You have to rebuild it using Recovery mdeia or ignite tape.

HTH,
Vince