Serviceguard

Need to change Cluster lock disk on a two node service guard HP-UX cluster.

 
Ajay S
Advisor

Need to change Cluster lock disk on a two node service guard HP-UX cluster.

Hello Folks,

WE are migrating storage and I need to change Cluster lock disk on a two node service guard HP-UX cluster.

here is how my setup and plan looks like. i want some export eyes to look at and provide thier advice. if i need to make any changes.

amd i also want to know if i need to halt the cluster for this activity?

 

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OS version:                         HP-UX 11.31 HA OE

Service Guard version:  11.20

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Current config related to lock VG (VGLOCK) on both nodes.

Node1   (current active node)

FIRST_CLUSTER_LOCK_VG           /dev/vglock

FIRST_CLUSTER_LOCK_PV /dev/disk/disk24

VOLUME_GROUP           /dev/vglock

Node2

FIRST_CLUSTER_LOCK_VG           /dev/vglock

FIRST_CLUSTER_LOCK_PV /dev/disk/disk24

VOLUME_GROUP           /dev/vglock

----------------------------------------------------------------------------------      

The device file names are same (/dev/disk/disk24) on both the nodes.

Vglock is disabled on both the nodes.

vgdisplay: Volume group not activated.

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I presented a new disk for quorum lock but device file names are not consistent for the same LUN.

On node 1:                          /dev/disk/disk83

On node 2                           /dev/disk/disk365

 

My plan is:

  • Create a new VG /dev/vglock1 on node 1 and add /dev/disk/disk83 to it
  • Activate vglock1.
  • Export in preview mode and copy the map file on second node.
  • Import vglock1 on second node (node2)               ( it will import it using device file /dev/disk/disk365)
  • Activate vglock1 in exclusive mode on first node (node1)
  • Gather cluster information and generate an asci file using cmquerycl.

       Cmquerycl –v –C mycluster.ascii –n node1 –n node2

  • Edit the ascii file and make changes as 

Node1   (current active node)

FIRST_CLUSTER_LOCK_VG           /dev/vglock1

FIRST_CLUSTER_LOCK_PV /dev/disk/disk83

VOLUME_GROUP           /dev/vglock1

Node2                                  

FIRST_CLUSTER_LOCK_VG           /dev/vglock1

FIRST_CLUSTER_LOCK_PV /dev/disk/disk365

VOLUME_GROUP           /dev/vglock1

  • Run cmcheckconf

Cmcheckconf –v –C mycluster.ascii

  • Apply cluster config

Cmapplyconf –v –C mycluster.ascii

  • Verify that cluster config using cmviewcl

 

4 REPLIES 4
Patrick Wallek
Honored Contributor

Re: Need to change Cluster lock disk on a two node service guard HP-UX cluster.

Here's my documentation to change the cluster lock disk:

 

 

Modifying Cluster Lock Disk / Cluster Lock VG configuration

  1. Locate the current cluster ASCII file. If its whereabouts is unknown, recreate it on one of the nodes using the cmgetconf command.

# cd /etc/cmcluster

# cmgetconf cluster.ascii

2. Insure the cluster.ascii reflects the current hardware and network configuration:

# cmcheckconf -C cluster.ascii

If this command fails, the cluster.ascii may be out-dated.

3 Locate the FIRST_CLUSTER_LOCK_VG and FIRST_CLUSTER_LOCK_PV references in the cluster.ascii file.

If the FIRST_CLUSTER_LOCK_VG reference will be changed, and it is a new volume group for the cluster, insure that each node can see the same set of disks for that volume group. See the /etc/lvmtab on each node.

                Then add the volume group name to the cluster.ascii file. For example:  

VOLUME_GROUP           /dev/<vgname>

4 Update the FIRST_CLUSTER_LOCK_VG reference and/or FIRST_CLUSTER_LOCK_PV references in the cluster.ascii file.

If updating the FIRST_CLUSTER_LOCK_PV - Make sure you do it for ALL nodes in the cluster. There should be a FIRST_CLUSTER_LOCK_PV line for EACH cluster node in the cluster ascii file.

5 When a maintenance window arrives, halt the cluster:

# cmhaltcl -f

6 Turn off cluster aware bit for the VG and then activate the cluster lock VG.

# vgchange -c n <vgname>

# vgchange -a y <vgname>

 7 Use the cmapplyconf command to generate a new cluster binary. This command performs a cmcheckconf validation of the cluster.ascii file, then updates and distributes the cluster binary file to all cluster nodes:

# cmapplyconf -f -C cluster.ascii

Begin cluster verification...

Modifying node <nodeA> in cluster <ClusterName>

Modifying node <nodeB> in cluster <ClusterName>

It should not be necessary to delete the cluster (cmdeleteconf ) prior to changing the cluster lock volume group or disk.

8Deactivate VG and make cluster aware again:

# vgchange -a n <vgname>

# vgchange -c y <vgname>

9 Restart SG

# cmruncl -v -n <nodename1> -n <nodename2>

10 Verify cluster lock configuration with 'cmviewcl -v' command and look for the "Cluster_Lock_LVM" section.

Ajay S
Advisor

Re: Need to change Cluster lock disk on a two node service guard HP-UX cluster.

Patrick, Thanks for responding back tp me and sharing the information.

so I need to halt the cluster to make this change? I read in one on the forum posts that in SG 11.19 and higher, it can be done online.. just wanted to make sure that.

Thanks Again!

Ajay

Patrick Wallek
Honored Contributor

Re: Need to change Cluster lock disk on a two node service guard HP-UX cluster.

That very well may be true.  This document was for a customer of mine that has HP-UX 11.11 and SG 11.16 (I think).

 

I haven't researched for SG 11.19.

henrygomez
New Member

Re: Need to change Cluster lock disk on a two node service guard HP-UX cluster.

Hi my friend, did you reemplace you lock disk????