How to remove alt boot path and disk

[David Johnson_6]

Actual had 2 questions.
1.) how to make system boot with being there if orig or al boot disk failes. something with mkboot.

2.) how to remove alt boot path and disk.

[Ashwani Kashyap]

1. if both the orig. and the alt. disk fails then the system is unbootable . Use an ignite tape or a bootable/recovery CD from HPUX to boot .

2. use set boot when the system is running or change the path from the PDC menu when the system is rebooting .

[Mel Burslan]

I could not quite understand what you mean by your question 1. You want to boot when your primary and alternate boot drives both fail. Right ? But from where ??
mkboot just writes boot information on disks, it has nothing to do with the actual boot event or sequencing as far as I know. The command to change where the system gets booted off is accomplished by setboot command or from the main bootstrap loader menu (can't remember which options one needs to dwelve into)

as an answer to your second question, I am not sure if you can remove the alternate boot disk using setboot command but if you do not want to have one, I think you can set it to the same disk as your primary boot path.

I know these are not the answers you are looking for but I hope it steers you towards the direction you need.

[curt larson_1]

well if you set autoboot and autosearch flags
the system will do a seach for possible boot devices and try to boot the first one it finds.

the problem is which is going to be the first one it finds. this isn't always deterministic

[David Johnson_6]

1.) sorry. was suppose to be.
How to make system boot without+ user input, if the primary OR alt boot disk is bad.

[Naveej.K.A]

hi david,

Alternate boot path is defined in the secondary storage area of the PDC, so that the system can boot, if the PDC is not able to detect or see the disk in the primary boot path. Means not in all case, if your disk in the primary boot path fails, the system would boot directly from the disk in the secondary boot path.

Suppose you got some bad blocks in the disk in the primary boot path, the system will boot from pri boot path only as the PDC is able to detect the disk in the prim path. In this case, for the system to boot from alt boot path, either you have to remove the disk in the pri boot path or boot pri from the BCH menu.

with best wishes
Naveej

[Geoff Wild · Accepted solution]

If your primary and alt disks are bad - then the system will not boot - it will sit at the GSP. Unless you have a third mirror?

Removing is easy:

1) If the disk is completely "dead", such as if you run ioscan and status is "no_hw" then you can hot swap the disk online.

2) However in circumstances where the disk has not fully failed please do one of the following to avoid data corruption :

a) reduce mirror before replacing the disk
b) deactivate VG before replacing the disk
c) shutdown system to replace the disk


After failed disk has been replaced by HP (assuming the disk is c1t5d0):

vgcfgrestore -n /dev/vg00 /dev/rdsk/c1t5d0

mkboot /dev/rdsk/c1t5d0

mkboot -a "hpux -lq (;0) /stand/vmunix" /dev/rdsk/c1t5d0

vgchange -a y /dev/vg00

lvlnboot -Rv /dev/vg00

vgsync /dev/vg00



Configuring Autoboot Options:

HP-UX: setboot -b on or setboot -b off command, to turn on (enable) or turn off (disable) autoboot.
setboot by itself to see current setting.


Rgds...Geoff