topic Re: Red Hat Clustering - LVM in Operating System - Linux

Red Hat Clustering - LVM

MikeL_4 — Mon, 16 Nov 2009 13:19:49 GMT

I've just installed Red Hat Cluster Server software on two Red Hat nodes. We are using one server as a primary database server with the other node as a standby server..

We are Using LVM with ext3 logical volumes.

My question is what the procedure would be to shutdown the logical volumes and Volume Group on the primary server, and move it to the backup server ?

The disk are visable on both servers currently, and /dev/mapper shows the Volume Group and Logical Volumes that are defined..

Just wondering the proper commands and sequence of commands to move from server to server..

Thanks

Re: Red Hat Clustering - LVM

Tim Nelson — Mon, 16 Nov 2009 18:52:34 GMT

I believe the shared filesytems need to be GFS filesystems, or at least some type oc cluster aware FS, and obviously shareable via SAN.

Once configured in the cluster these will failover with your cluster package.

Re: Red Hat Clustering - LVM

Serviceguard for Linux — Tue, 17 Nov 2009 14:34:41 GMT

I don't believe that GFS is a requirement, although it will certainly work. I believe there is an LVM Resource Agent. That can be used to move the appropriate VGs.

Re: Red Hat Clustering - LVM

Steven E. Protter — Tue, 17 Nov 2009 17:19:37 GMT

Shalom,

GFS lets the filesystem be mounted from both nodes. Seems you don't want that.

Then you need to do it kind of serviceguard style.

vgchange -a n vg## # on the node giving it up.

vgchange -a y vg## # on the receiving node.

You can build this step into the startup script for the application.

SEP

Re: Red Hat Clustering - LVM

Tim Nelson — Tue, 17 Nov 2009 19:53:55 GMT

Sorry about that guys, I had a one track mind yesterday.

The RH clustering admin and RH LVM admin guide have the best info.

http://www.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5.4/html/Logical_Volume_Manager_Administration/index.html

Re: Red Hat Clustering - LVM

loco_vikide — Tue, 17 Nov 2009 22:30:45 GMT

Assuming that you are using latest version of RedHat cluster (5.x), you should configure the floating logical volumes in a cluster package and let the Redhat cluster lvm daemon manages the proper failover/failback of the logical volumes between cluster nodes.

The command you could use to move cluster package from node to node, given that the cluster and the package are up and running:

# clusvcadm -r your_package_name -m your_secondary_hostname.

Refer to the man pages for the handy RedHat cluster commands:
clusvadm
clustat
cman_tool
ccs_tool
ccs_test
rg_test

Cheers

Re: Red Hat Clustering - LVM

MikeL_4 — Wed, 18 Nov 2009 13:33:07 GMT

Thanks