topic Re: automatic boot form alternate bootdisk in Operating System - HP-UX

automatic boot form alternate bootdisk

Konrad Hegner — Mon, 22 Oct 2001 14:22:52 GMT

Hello

I have a mirrored disksystem. It is possible to boot from the alternate bootdisk, if the primary bootdisk crashed, without handling it manual?

It works fine with 'bo alt', but this is interrupt the bootsequenz. I will start this without manual interrupting.

Thank you Koni

Re: automatic boot form alternate bootdisk

Jim Turner — Mon, 22 Oct 2001 14:34:20 GMT

Hi Koni,

You need to add a step to your boot disk mirroring procedure. Here's the one I use:

For this example, the original boot disk is /dev/dsk/c0t6d0 (8/4.6.0), and the
new mirror disk is /dev/dsk/c0t5d0 (8/4.5.0).

# Prepare bootable disk.
pvcreate -B -f /dev/rdsk/c0t5d0

# Add the new disk to /dev/vg00.
vgextend /dev/vg00 /dev/dsk/c0t5d0

# Write boot (LIF) info to the disk.
mkboot /dev/rdsk/c0t5d0

# Update AUTO file on both disks so vg00 will activate without a quorum.
mkboot -a "hpux -lq" /dev/rdsk/c0t5d0
mkboot -a "hpux -lq" /dev/rdsk/c0t6d0

# Mirror each lvol in vg00.
# The order of the first three is very important!
lvextend -m 1 /dev/vg00/lvol1 /dev/dsk/c0t5d0
lvextend -m 1 /dev/vg00/lvol2 /dev/dsk/c0t5d0
lvextend -m 1 /dev/vg00/lvol3 /dev/dsk/c0t5d0
lvextend -m 1 /dev/vg00/lvol4 /dev/dsk/c0t5d0
.
.
.
lvextend -m 1 /dev/vg00/lvolx /dev/dsk/c0t5d0

# Recover BDRA
lvlnboot -R

# Set BOOT, SWAP, and ROOT.
lvlnboot -b /dev/vg00/lvol1
lvlnboot -s /dev/vg00/lvol2
lvlnboot -r /dev/vg00/lvol3

# Check stable storage.
setboot

# If boot paths and switches are not set properly,
# perform the following as needed.
setboot -p 8/4.6.0 # Primary boot path
setboot -a 8/4.5.0 # Alternate boot path
setboot -s on -b on # Activate autosearch and autoboot

During a "normal" reboot, the primary boot disk will be used. If the system
boots and the primary boot disk has failed, the system will automatically boot
off of the alternate boot disk.

All the best,
Jim

Re: automatic boot form alternate bootdisk

Sridhar Bhaskarla — Mon, 22 Oct 2001 14:37:07 GMT

Konrad,

No. If the primary disk fails, nothing will happen and the system will continue to run with the mirror disk.

You can't boot automatically from the desired disk during the system crash. But I would suggest you to set the boot path to alternate so that when the system boot next time, it will boot from the alternate disk to ensure proper functionality of mirroring. I would do this through startup script. It switches the alternate path from current by setboot command during the startup.

However, there is a danger again doing this way. If you setboot to alternate and if alternate fails and the system reboots, it won't boot.

-Sri

Re: automatic boot form alternate bootdisk

Jim Turner — Mon, 22 Oct 2001 14:38:05 GMT

PS - Please forgive my unclean cut-n-paste. If the forum posting mechanism wasn't totally brain-dead, it would have known what to do with and which would have made the "r" in "rdsk" bold-face.

Re: automatic boot form alternate bootdisk

Patrick Wallek — Mon, 22 Oct 2001 14:41:12 GMT

Hmmmmm......I didn't think that the system would boot from the alternate automatically.

Check out TKB document KBAN00000231 "Series 800 boot menus and procedures"

Here is an excerpt from that document:

"The Boot ROM initializes the primary boot path, loads ISL, and allows one to select either the manual or autoboot mode. In manual mode, the user can select the boot device from all the available peripheral devices. In
autoboot mode, the Boot ROM automatically boots the operating system from the primary boot path defined in Stable Storage"

Re: automatic boot form alternate bootdisk

Sridhar Bhaskarla — Mon, 22 Oct 2001 14:46:47 GMT

I had a bit of bitter experience of having "auto search" (setboot -s) on my workstation. If by any chance the CD ROM has a boot CD or if you have some network ignite servers, there is a chance that the system may boot from them during the reboot. So, I would suggest to turn-off auto search method.

But Mike, you don't need to worry about it as the system will continue to be up and running with the mirror disk in case of primary disk failure.

-Sri

Re: automatic boot form alternate bootdisk

Sanjay_6 — Mon, 22 Oct 2001 14:48:16 GMT

Hi,

your system will boot from the mirror disk, if the disk is configured as bootable and is set as laternate boot path in the system configuration.

Here is a thread for more info.

http://us-support.external.hp.com/cki/bin/doc.pl/sid=7159cafb034f90ca0b/screen=ckiDisplayDocument?docId=200000056385778

Hope this helps.

thanks

Re: automatic boot form alternate bootdisk

Jim Turner — Mon, 22 Oct 2001 14:49:07 GMT

Hi Pat,

I won't swear to it, but I think I've had a pri bo path bite it, and had the machine come up with no fuss on the alternate at boot after the panic. If I'm not mistaken, the equivalent of a "sea ipl" is done at boot time. If autoboot is on and autosearch is on and no boot LIF can be found on the pri bo path and the AUTO file contains "hpux -lq", I believe the alt bo path is used without intervention.

I think?

Maybe?

I need a beer :-)
Jim

Re: automatic boot form alternate bootdisk

Marco A. Vicente — Thu, 25 Oct 2001 12:32:04 GMT

PROBLEM
Although autoboot is turned 'on', it does not work for the
mirrored vg00. It has also been verified that the alternate
bootpath is properly set.

Why doesn't the autoboot work?

CONFIGURATION
Operating System - HP-UX
Version - 11.0
Hardware System - HP9000
Series - D370
Subsystem - System Administration

RESOLUTION
autoboot does not work because neither the D-, K-, or T-Class
servers can autoboot from an alternate path. These servers can
only autoboot from the default path (8/4/5).

To resolve the problem:
1. Change the primary path to 8/8.
2. Change the alternate path to 8/4/5.
Once these changes are made, the system will autoboot when the primary path is unavailable.