topic Re: Mirroring root in Operating System - HP-UX

Mirroring root

John Pyle — Thu, 22 Feb 2001 00:25:16 GMT

I went back to check my system after reading the document KBAN00000036 Mirrored Root Disks -- common misconceptions. This is what I found. When I run the setboot command it returns:

Primary bootpath : 10/0.6.0
Alternate bootpath : 10/12/5.0.0

Autoboot is ON (enabled)
Autosearch is ON (enabled)

The command lvlnboot -v returns:

Boot Definitions for Volume Group /dev/vg00:
Physical Volumes belonging in Root Volume Group:
/dev/dsk/c0t5d0 (10/0.5.0) -- Boot Disk
/dev/dsk/c0t6d0 (10/0.6.0) -- Boot Disk
Boot: lvol1 on: /dev/dsk/c0t5d0
/dev/dsk/c0t6d0
Root: lvol3 on: /dev/dsk/c0t5d0
/dev/dsk/c0t6d0
Swap: lvol2 on: /dev/dsk/c0t5d0
/dev/dsk/c0t6d0
Dump: standswap on: /dev/dsk/c0t6d0, 0
Dump: lvol2 on: /dev/dsk/c0t6d0, 1

I tried to run the mkboot command to set the alternate disk to be c0t5d0 but it does not change the output of setboot.

mkboot -a "hpux -lq (10/0.5.0;0)/stand/vmunix" /dev/rdsk/c0t5d0

Must I recreate vg00 from scratch? I checked both of my servers and they each show this configuration. The strange thing is that one of the servers does not have a device at address 10/12/5.0.0 yet it shows up in the setboot. I think I must have missed a step somewhere.

Re: Mirroring root

Patrick Wallek — Thu, 22 Feb 2001 00:38:32 GMT

You should be fine. Running the mkboot command only makes the disk you specify bootable. It does not set the alternate boot disk path. Therre is a command you can run to do that, but since I'm at home I can't research the command. That has to be set manually. You can also set the alternate boot path when you reboot the system by interupting the boot.

When you interupt the boot it also lets you boot from a different disk if your boot paths are not correct. If your primary boot disks fails, then you will have to interact with the boot anyway since it will not automatically boot from the alternate boot path.

As long as lvlnboot shows that both disks are boot disks, and vgdisplay shows that all lvols are synced, then you are fine.

You do NOT need to recreate VG00 from scratch.

Re: Mirroring root

James R. Ferguson — Thu, 22 Feb 2001 00:48:37 GMT

Hi John:

See the man pages (1M) for 'setboot'. 'setboot' allows you to set (or display) the alternate boot path; the primary boot path; to enable/disable autosearch and/or to enable/disable autoboot.

...JRF...

Re: Mirroring root

Peggy Fong — Thu, 22 Feb 2001 03:53:44 GMT

John

The others have given you the command - here's the syntax to set your alternate boot path to match your mirror boot disk

setboot -a 10/0.5.0

You can change them at anytime while the system is running.

To verify the contents of your AUTO file on your bootable disks execute the following:

lifcp /dev/rdsk/c0t5d0:AUTO -

The - is standarc out and should show something like: hpux
or
hpux -lq (10/0.5.0;0)/stand/vmunix

If you are on 10.20 or above (maybe even 10.X) you do not need to specify any path or kernel. So "hpux -lq" would suffice.

Repeat for your other disk

lifcp /dev/rdsk/c0t6d0:AUTO -

You can also verify that the LIF area is populated with the HPUX and ISL and other things needed to boot a system by using the following commands:

lifls -l /dev/rdsk/c0t6d0
lifls -l /dev/rdsk/c0t5d0

You do not need the -l option - works like ls.

I think you are in good shape, just need to change that alternate boot path to match your disk.

I don't know about the rest of you but I usually leave Autosearch OFF (yours is ON).
Hope this helps,
Peggy

Re: Mirroring root

John Waller — Thu, 22 Feb 2001 08:25:44 GMT

mkboot makes the bootarea of the disk and does not set the boot path.
As mentioned you use setboot to change your primary and alternate boot paths when the system starts. (You can also change these values by stopping the boot within 10 seconds when you first switch on your system).
If you have loaded the DIAGNOSTICS pack you may have a difference when you perform the lifls -l /dev/rdsk/c0t5d0 and c0t6d0 disks. If you seem to be missing some files try these commands on the disk with the missing files to update the lif info:

cd /usr/sbin/diag/lif

mkboot -b updatediaglif -p ISL -p HPUX -p LABEL -p AUTO /dev/rdsk/c0t(5 or 6)d0.

Re: Mirroring root

unixdaddy — Thu, 22 Feb 2001 10:33:37 GMT

In your mail you say that you are trying to set the alternate path. Why are you using mkboot for that? shouldn't you be using the 'setboot -a altenate path' command to set this?