un mirrror or Split the mirror

[Asif_8]

Hi !
Server = rp2405
Os =hp-ux11i
2 disk 36 Gb
Group vg00
I want un mirror the disk or volume I want to use 2nd disk for other purpuse
how to split or un mirrior the disk. how to user mirror disk for other application
thanks

[Karthik S S · Accepted solution]

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=305908

More results from ITRC,
http://tinyurl.com/2snnl

-Karthik S S

[Shaikh Imran]

Hi,
Be careful if you are trying to remove the mirror of the root disk.

DO-NOT-FORGET TO USE lvlnboot -R if you are doing it for root VG.
1)Remove the LV's from the mirror
#/usr/sbin/lvsplit [-A autobackup] [-g PhysicalVolumeGroup] lv_path ...


Up to 127 logical volumes can be specified on the command line. All logical volumes must belong to the same Volume group.

2)Reduce the Volume group to 1

#vgreduce vg01 /dev/dsk/cxtxdx.

Now you can sucessfully remove the disk

Regards

[Rajeev Shukla]

Reduvfce the mirror copy to 0 and then you can use the disk, First choose the disk you want to use for your purpose and remove from root mirror.
use

for i in `vgdisplay -v vg00|grep "LV Name"|awk '{print $3}'`
do
lvreduce -m 0 $i /dev/dsk/
done

Then do a vgreduce and remove that disk from root vg.
vgreduce /dev/vg00 /dev/dsk/

You can then use your disk

[jayan_3]

One More Very IMPORTANT Task is to update the lvm bootinformation using the

lvlnboot -R command

all the best

wip

[Sanjiv Sharma_1]

Hi Asif,

This post has the steps:
http://forums1.itrc.hp.com/service/forums/parseCurl.do?CURL=%2Fcm%2FQuestionAnswer%2F1%2C%2C0x6967c1c4ceddd61190050090279cd0f9%2C00.html&admit=716493758+1080539101782+28353475

hth.

[Trond Haugen]

As you have already got the answer to your question I would considder this.
2 x 36 GB shlould leave some space even with all the system volumes mirrored. On option might be keeping that and creating new lvols that are not mirrored.

Regards,
Trond

[Asif_8]

thanks all of them
1. after unmirror. I want to erase every data from 2nd disk and create knew volume

2.what is differen Lvreduce or lvsplit command

[Michael Tully]

One of the links provided is somewhat confusing.

To unmirror:
lvreduce -m 0 /dev/vg00/lvolX (for each logical volume)

To remove the disk from the volume group
vgreduce /dev/vg00 /dev/dsk/cXtYdZ (substitute you disk)

The difference is that 'lvreduce' removes the mirror, whilst 'lvsplit' splits a mirrored pair for the purpose of creating a backup. The man pages for these commands will provide further information. To use the disk, you can create another volume group. e.g. below
mkdir /dev/mygroup
mknod /dev/mygroup/group c 64 0x020000
vgcreate -p 128 /dev/mygroup /dev/dsk/cXtYdZ
lvcreate -n myvol /dev/mygroup
lvextend -L /dev/mygroup/myvol

See man pages for further details. Once you 'lvreduce/vgreduce' the mirror and disk, the data has gone.

[Sanjiv Sharma_1]

Hi,

Run the following command
# pvcreate -f /dev/rdsk/cxtxdx
cxdxtx is the device file for the disk you want to erase data.
# mkdir /dev/vg05 (vg05 is new vgname)
# mknod /dev/vg05/group c 64 0x050000
# vgcreate /dev/vg05 /dev/dsk/cxdxtx
# lvcreate -L 20000 /dev/vg04
# newfs -F vxfs -o largefiles /dev/vg05/rlvol1
# mkdir /newpountpoint (mount point as per your requirement)
# mount /dev/vg05/lvol1 /newmountpoint

This completes the task.

Difference betwen lvreduce and lvsplit
lvreduce --> decrease space allocation or the number of mirror copies of logical volumes
lvsplit --> split mirrored LVM logical volume into two logical volumes

Do man lvreduce and man lvsplit for more details.

hth.

[Sanjiv Sharma_1]

Oppsssssss..

# lvcreate -L 20000 /dev/vg04

You can create single 36 GB lvol or multiple smaller size lvol

Say lvol1 20 GB and lvol2 16 GB
# lvcreate -L 16000 /dev/vg04

Create new filesystems on each and mount them on seperate filesystems.

[Asif_8]

thanks again !



To break the mirror..
# lvreduce -m 0 /dev/vg00/lvol2 /dev/dsk/c2t2d0
# lvreduce -m 0 /dev/vg00/lvol1 /dev/dsk/c2t2d0
# lvreduce -m 0 /dev/vg00/lvol3 /dev/dsk/c2t2d0
==> Repeat for the rest of the lvols.
# vgreduce vg00 /dev/dsk/c2t2d0
# lvlnboot -v

can i Run lvlnboot -R

asif