Renaming an LV in clustered environment Online

[Victor_101]

Hi Guys ,
I have MCSG with 9i RAC extension.I had previously created all Raw Files systems sitting on Logical volumes at the time of implementation in view of future requirements. The this is now that as per common requirements i need to resize or rename some of the LVs which are in the VGs which are shared across the node as per Oracle RAC requirement.
How does that reflect in the below procedure for renaming an LV ? Do I need online JFS ?

Renaming a logical volume
/dev/vgdata/lvol1 -> /dev/vgdata/data_lv
umount /dev/vgdata/lvol1
ll /dev/vgdata/lvol1 take note of the minor ( e.g 0x010001 )
brw-r----- 1 root root 64 0x010001 Dec 31 17:59 lvol1
mknod /dev/vgdata/data_lv b 64 0x010001 create new logical volume name
mknod /dev/vgdata/rdata_lv c 64 0x010001
vi /etc/fstab { reflect the new logical volume }
mount -a

rmsf /dev/vgdata/lvol1
rmsf /dev/vgdata/rlvol1


By the way , I have an EVA 3000 SAN over Fiber and the VGs in question are on that SAN. I am Running HP-UX 11 V1 (11.11) on a pair of 5470s.
Please advise ASAP.
Thanks
Victor

[Thayanidhi]

When you say raw volume, there is no file system on it!!
You can't umount them (not mounted at all).

When VG activated the raw volumes are available.

I doubt your procedure is totally wrong.

I would do below.

1. Stop the applications and cluster.
2. De-activate the VG from one node and export the VG
3. De-activate the VG in other node and make is unshared/unclustered (-C n -S n in vgchange)
4. Do all the lvm activities now after activating in normal mode.
5. preview the export with map file and copy the map file to other node.
6. Make the Vg shrable now.
7. Import the VG in other node using the copied map file.
8. Activate (or start the package)

Regds
TT

[Victor_101]

HI TT ,
thanks for the try .. but my main requirement is to have this ONLINE. without bringing down my system ,cluster, etc..
or atleast need to stop just the bare minimum.

besides that i guess your procedure is right. I would prefer if there is an alternate software to manage this ? maybe like i mentioned the Online JFS to manage this and also if i can just add the software and have this functionality without altering the current setup, as my Oracle Apps cannot afford to go down for very long . even if planned.

Regards,
Victor

[Geoff Wild]

First off - if it is controlled by MC/SG - then it shouldn't be in /etc/fstab.

You can do this - as long as you are not monitoring the filesystem from MC/SG.

I just tested this:

lvcreate -L 100 /dev/vg00
mkfs /dev/vg00/rlvol13
mkdir /mymount
mount /dev/vg00/lvol12 /mymount

umount /mymount
mv /dev/vg00/lvol13 /dev/vg00/lvmy
mv /dev/vg00/rlvol13 /dev/vg00/rlvmy
mount /dev/vg00/lvmy /mymount

And it worked...

Rgds...Geoff

[Kyris]

Please have a look at an extract from my note book, which I hope will help u in some way..

Modifying an LV
----------------

To increase an LV from 500MB to 800MB do : I go to single user mode â -> I have no OnlineJFS

$ mount /usr [need bdf]
$
$ lvextend â L 800 /dev/vg04/lvol1 [ /dev/dsk/c0t4d0 ]
$
$ extendfs /dev/vg04/lvol1

$ mount /dev/vg04/lvol1 /kakos - to see it and then reboot

[ fsadm â b ]


Rename an LV:
---------------

umount /dev/vg04/lvol1
mv /dev/vg04/lvol1 /dev/vg04/lvol22
mv /dev/vg04/rlvol1 /dev/vg04/rlvol22
mount /dev/vg04/lvol22 /kakos


Rename a VG:
--------------

umount /dev/vg04/lvol1 etcâ ¦..

vgchange â a n vg04
vgexport â m /tmp/mapfile vg04
ll /dev/*/group
mkdir /dev/vgnew
mknod /dev/vgnew/group c 64c 0x060000
vgimport -m /tmp/mapfile vgnew /dev/dsk/c0t4d0 /dev/dsk/c0t5d0
vg

[Kent Ostby]

Victor --

You should just be able to move the files to the new names:

cd /dev/vgdata
mv lvol1 data_lv
mv rlvol1 rdata_lv

The PROBLEM with this is how is your APPLICATION accessing the lvol. How does it know to use that lvol name ? And, if you make a change, can you do that with your application online. My guess is that you won't be able to since the application has probably opened a specific filename to access the data.

As for it being in SG, this will generally only be true if it has a filesystem on it.
Otherwise, SG is just starting up the VG for you.

Best regards,

Kent M. Ostby

[Victor_101]

For those who are a bit lost, i am runnin the ORACLE 9i RAC extension of the MCSG , so the there's no File systems as some of you noticed and not mounted. Just raw volumes and Oracle accesses the Character device.... i need to do this online. I was told this was all possible with Veritas Clustered File System, the thing is that when we implemented last year, Veritas CFS was not supported on my EVA3000.