topic Re: how to break mirroring ? in Operating System - HP-UX

how to break mirroring ?

Shah Gaurang B. — Wed, 03 May 2006 01:45:19 GMT

Hi,

how to break mirroing in rp series server ? Presently both disk are fine but i want to release one disk for other purpose.

Re: how to break mirroring ?

Warren_9 — Wed, 03 May 2006 01:50:10 GMT

hi,

1. reduce the mirror copy of the LV
# lvreduce -m 0 $LV $PV

2. remove the PV from the VG
# vgreduce $VG $PV

3. re-initialize the PV
# pvcreate -f $PV

GOOD LUCK!!

Re: how to break mirroring ?

Senthil Kumar .A_1 — Wed, 03 May 2006 03:06:08 GMT

Hi,

Refer to section 5 in the below link,

http://www.governmentsecurity.org/articles/articles2/When_Good_Disks_Go_Bad.pdf_fl/When_Good_Disks_Go_Bad.html

Regards,
Senthil Kumar .A

Re: how to break mirroring ?

Ninad_1 — Wed, 03 May 2006 03:19:15 GMT

Gaurang,

If this is your root mirror disk, I would strictly advise not to remove the mirror.
But if it is some other mirror disk, then check which lvols are mirrored -
for i in `vgdisplay -v /dev/vgxyz | grep 'LV Name' | awk '{print $NF}'`
do
if [[ $(lvdisplay -v $i | grep 'Mirror' | awk '{print $NF}') != "0" ]]
then
echo $i is mirrored
fi
done

Then use the method Warren has shown to reduce mirror copies of all mirrored volumes and proceed , reduce VG - to remove disk from VG and then the disk is free to be used for you.

Regards,
Ninad

Re: how to break mirroring ?

JASH_2 — Thu, 04 May 2006 04:07:23 GMT

Shah,

The best way I find to break mirrors is to get my mother in law to look at them!

Just a bit of fun.

JASH

Re: how to break mirroring ?

Raj D. — Thu, 04 May 2006 04:24:12 GMT

Shah ,

# lvreduce -m 0 /dev/vg00/lvol1 /dev/dsk/c?t?d?
- do for all the lvs .

# vgreduce /dev/vg00 /dev/dsk/c?t?d?

Now the disk is free. Mirror broken.

Cheers,
Raj,

Re: how to break mirroring ?

Raj D. — Thu, 04 May 2006 04:26:48 GMT

Shah,

To find out which disk is the primary boot disk, and the system is booted from :

Use:

# echo "boot_string/S" | adb /stand/vmunix /dev/kmem

Cheers,
Raj.

Re: how to break mirroring ?

Ajitkumar Rane — Thu, 04 May 2006 04:51:04 GMT

Gaurang,

I assume your VG which u want to unmirror is not a rootvg

lvdisplay -v /dev/vgname/lvolname
note the device files of the disks used for the LVs
decide which disk to remove,

note the number of mirror copies, if 1 then use m 0 if 2 then m 1....

lvreduce -m 0 /dev/vgname/lvoln /dev/dsk/cxtydz

When all the lvols are reduced from the disk

vgreduce /dev/vgxx /dev/dsk/cxtydz.

Check vgdisplay/pvdisplay to confirm the disk is out of the Vg.

Good Luck

Ajit