Boot disk replacement !.

[rveri]

Hi ,

I have boot disk that is mirroed with another.
Now got syslog error message [ SCSI: Read error -- dev: b 31 0x029000, errno: 126, resid: 2048 ] for the first bootdisk. And that is the disk the os is booted from.

got from this command:
[ # echo 'boot_string/S'| adb /stand/vmunix /dev/kmem ]


1. Now ,What is the procedure to replace this boot disk.
2. One package is running on it. (MC/SG)
2. Does it need any outage.

Thanks.

[Antonio Cardoso_1]

Hi,

you can get general information on this topic in http://docs.hp.com/en/5991-1236/When_Good_Disks_Go_Bad.pdf

and also check these threads:
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1007553
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1001813

HTH,
antonio.

[rveri]

Antonio,

I got this document :
http://docs.hp.com/en/5991-1236/When_Good_Disks_Go_Bad.pdf

But not helped much for this case,

Thanks,

[Antonio Cardoso_1]

Hi,

I already used a procedure as described in second thread by Geoff Wild, with no outage.
However, I've not MC/SG, and don't know if some additional/different actions are required by this.

regards,
antonio.

[Shaikh Imran · Accepted solution]

Hi,

Try booting the system in LVM maintenance mode from the alternate root mirror disk to perform the LVM recovery.

Interrupt the boot process and from the command menu, type the boot command specifying the hardware path of the alternate boot disk as in the following example where PATH is the physical path for
the alternate boot disk:

bo PATH

Answer Y if prompted to interact with ISL.

At the ISL prompt, enter the hpux command to bootup into LVM
maintenance mode using the no-quorum option:

ISL> hpux -lm -lq

Restore the LVM configuration to the replaced primary root disk from the
vgcfgbackup of the root volume group LVM configuration.

For example, if c0t6d0 is the primary root disk replaced:

# vgcfgrestore -n /dev/vg00 /dev/rdsk/c0t6d0

Execute the mkboot and lvlnboot commands to add the boot information to the primary root disk and synchronize the BDRA as in
the following example:

# mkboot /dev/rdsk/c0t6d0
# mkboot -a "hpux" /dev/rdsk/c0t6d0
# lvlnboot -R /dev/vg00

Activate the root volume group:

# vgchange -a y /dev/vg00

will display "successfully changed" if the volume group is successfully activated.

NOTE: If the vgchange command fails with "couldn't attach to volume group" or "cross-device link" errors for other physical volumes belonging to the root volume group, use the vgcfgrestore command to also restore the LVM configuration to each physical volume referenced in
these error messages. Before executing the vgcfgrestore command,the following command can be executed to just display the LVM configuration information from the /etc/lvmconf/vg00.conf file and verify that the physical volume in question is listed:

# vgcfgrestore -n vg00 -l

NOTE: The LVM kernel code detects if a failed Physical Volume (PV)has become available and will perform an automatic re-sync of the extents on this PV when the vgchange command is executed with
either the -a y or -a e options. If LVM doesn't see that the PV failed, no automatic synchronization of any mirrorred logical volumes is performed, and in those instances, a vgchange must be followed by a vgsync as in the following example:

# vgsync /dev/vg00

After the mirrors are re-synchronized from the vgchange or the vgsync commands, reboot the system and verify that able to bootup from the original root disk.


Hope this helps...

[Shaikh Imran]

Hi,

Please make sure that you shift that package to the other node before doing this
activity.

#cmhaltpkg
#cmmodpkg -e -n
#cmrunpkg -n
#cmhaltnode
#shutdown -r -y

Hope this helps ....

[rveri]

Thanks Shaikh ,
Thats pretty good and clear.

Well can I also do like that:

-Boot from the alternate disk fullly.
- bo alt_disk_path
- ISL > hpux -lq
- from Multiuser mode remirror the disk, and reboot.
( vgcfgrestore , vgchange -a y , mkboot .. , vgsync )

- restart and check.
-----------------------

If it will also work. any sugestion, What are the differences in this two process.

Thanks,

[rveri]

Thanks Your steps are looks very good. I will try when get a chance after getting the downtime and revert back.

Thaks(again).