Changing the cluster lock disk

[Terrence]

I've been searching the forums for the specific instructions on how to easily change the cluster lock disk and nothing is exactly what I need.

I have a happy healthy cluster and all I need to do is to change the cluster lock disk. I migrated all my data to a new SAN and new luns using the pvmove command. Now I have to change the cluster lock disk so I can remove the final lun from the old SAN. Both the current and proposed cluster lock disk are still in the volume group. I have only one VG in the cluster and it's unchanged as the cluster lock VG.

Here's my plan

cmhaltpkg -v pkg

vgchange -c n /dev/vg01

cmhaltcl

vgchange -a y /dev/vg01

cmdeleteconf -c clustername

I will then edit the /etc/cmcluster/cluster.ascii file to change the cluster lock disk on both nodes of the cluster.

cmcheckconf -v -C /etc/cmcluster/cluster.ascii

cmapplyconf -v /etc/cmcluster/cluster.ascii

cmruncl

Do I need to run cmapplyconf -P /etc/cmcluster/clustername/pckconf.ascii at this point? Nothing is changing in it.

cmrunpkg -v pkg

Is this plan sound?

Once everything is back up and running I'll just do a vgremove on the old cluster lock disk and map file the changes over to the other node.

[melvyn burnard]

Your plan looks good.
You do not need to delete the config with cmdeleteconf though.

Also, may be worth using cmviweconf to see what is listed in the binary both before and after the change.

[sujit kumar singh · Accepted solution]

Hi

Terrence,


all fine just to add few things:
1)take a backup of the /etc/cmcluster directory on both the nodes before doing the change.
2)I assume that none of the package is using the VG /dev/vg01 so in your steps you can try getting the "Last LUN" removed just after the vgchange -a y /dev/vg01 line making the use of #vgreduce /dev/vg01 .
3)create a map file and rcp that after you remove the Last LUN (of the Oldstorage that you are using as current Lock PV) Import the VG vg01 on the other node with this confign(removed OLD LUN).
4)If the VG vg01 had not been the part of any cluster packages then you need not change that in Package Control Files. in the package.conf file no modifications reqd assuming that this is a normal LVM SG package.
5)make sure that all the warnings and the Errors if occuring the cmcheckconf of the cluster ASCII file are properly addressed before doing the cmapplyconf.

6)but i am not too sure as you are making a cmdeleteconf -c cluster, i think you might need to a cmcheckconf and cmapplyconf for all the packages using cmcheckconf -P and cmapplyconf -P


7) Assuming the point 6 , i think you can easily do without the step that you have mentioned in for the cmdeleteconf -c clutser.
You do not require that. and also if you oit that you will sure not have to di a cmcheckconf and cmapplyconf of the package conf files, assuming also that vg01 is not being used by any package.


just few thoughts
sujit

[Johnson Punniyalingam]

Procedure to change the cluster lock disk.

First identify the cluster lock disk and then edit the cluster configuration file and change accordingly to reflect the new cluster lock disk.
do a cmcheckconf using the configuration file and then cmapplyconf

[Johnson Punniyalingam]

Hi Terrence,

Follow below steps to change cluster lock disk

Frist node
# pvcreate /dev/rdsk/c_t_d_
# mkdir /dev/vglocknew
# mknod /dev/vglocknew/group c 64 0x0100000
# vgcreate /dev/vglocknew /dev/dsk/c_t_d_"
# vgexport -pvs -m map.vglocknew /dev/vglocknew
# rcp map.vglocknew SECONDNODE:/etc/lvmconf

Second Node
# mkdir /dev/vglocknew
# mknod /dev/vglocknew/group c 64 0x0100000
# cd /etc/lvmconf
# vgimport -vs -m map.vglocknew /dev/vglocknew
# vgchange -a y vglocknew
# vgchnage -a n vglocknew

# cmgetconf cluster.ascii
# cp cluster.ascii cluster.ascii.backup

Edit following parameter in the ascii file.

FIRST_CLUSTER_LOCK_VG /dev/vglocknew
FIRST_CLUSTER_LOCK_PV /dev/dsk/c_t_d_
FIRST_CLUSTER_LOCK_PV /dev/dsk/c_t_d_
VOLUME_GROUP /dev/vglocknew


# cmcheckconf -C /etc/cmcluster/cluster.ascii"

Bring all package down
# cmhaltpkg

Bring cluster down.
# cmhaltcl -v

Activate the lock VG.
# vgchange -a y vglocknew

Apply new configuration file.
# cmapplyconf -f -C /etc/cmcluster/cluster.ascii"
# vgchange -a n vglocknew

Start the cluster.
# cmruncl -v
# vgchnage -c y /dev/vglocknew"
#cmrunpkg

Thx,
Johnson

[Terrence]

Thanks. I will drop the cmdeleteconf step, and the package check and apply as well.

Johnson's response raises these questions.

Do I need a vgchange -a n /dev/vg01 after I do the cmapplyconf.

And do I then need to vgchange -c y /dev/vg01 after I start the cluster with cmruncl?

[Johnson Punniyalingam]

Johnson's response raises these questions.

Do I need a vgchange -a n /dev/vg01 after I do the cmapplyconf.

>>YES, BECOZ , I would like the cluster to activate the VG , automatically when i start the Cluster,<<

And do I then need to vgchange -c y /dev/vg01 after I start the cluster with cmruncl?

Yes, In order to activate the /dev/vg01 has cluster aware disk.

(please refer man page vgchange -c for more info )

Thanks,
Johnson

[Johnson Punniyalingam]

And do I then need to vgchange -c y /dev/vg01 after I start the cluster with cmruncl?

"You need do vgchange -c y /dev/vg01

before you start Cluster using cmruncl command"

otherwise the Cluster will not start , becoz you haven't marked the disk has Cluster aware disk"

Hope this Clarify Your Questions

Thanks,
Johnson

[smatador]

Hi,
It depend on the release too, on SG 11.18 you can change the lock disk online
http://docs.hp.com/en/B3936-90122/ch08s03.html
With older release, if you have access to hp support you have cminitlock utility to change the lock disk online. I test it in the past, and the utility do the job.

[sujit kumar singh]

the main difference in what you have in the action plan and what johnson has suggested is that Johnson is creatting a new VG.

apart From that when you do a cmcheckconf and the cmapplyconf the Lock VG needs to be active(in exclusive or Normal mode)

The other part is that is that for a VG that is mentioned in the Volume_section of the Cluser ASCII file, when you do a cmapplyconf, SG maakes that Cluster Aware if you have not done that previously using the vgchange -c y .


regards
sujit