Volume Group activation on both nodes

[chindi]

Hi ,

Is it possible to activate same volume group on two nodes.  We have a requirement 

HPUX 11iv3 , No Service guard .

Is it safe to carry out such activity ? wont it corrupt filesystem ?

Do we have any third party software to do it ??

[Patrick Wallek]

I would not recommend this with normal LVM or VxVM.  If you activate the VG on both nodes there is a very good chance of corrupting data.

This is possible with a product like Oracle's Cluster File System (CFS).

http://www.oracle.com/us/technologies/linux/025995.htm

I do not know if Oracle CFS is available for HP-UX or not.

[Bill Hassell]

Sharing filesystems (and volume groups) between two or more systems guarentees corruption, usually resulting in a panic (system crash) to prevent further damage. To share filesystems requires a complex interaction between systems to coordinate updates and changes to various files, directories and metadata.

However, NFS handles all this quite well. You can share several filesystems with several clients.

[chindi]

Hi guys,

But what if NFS server fails ??

We have a requirement that same mount point will be accessed by 3 hosts simultaneously , if 1 host fails , other two hosts still must be able to work with application , its DRM solution .

What if its not possible with NFS too , then how do we approach this requirement ?

[Bill Hassell · Accepted solution]

What you are describing is a requirement for Service Guard. Two or more nodes can be clustered together such that the critical application and/or database will always be running. An NFS server, just like any single server (or the network path to the NFS server) is indeed vulnerable. Service Guard can cluster the 3 nodes, even if they are in different cities, and through storage replication, the data will always be available to the nodes. Your requirement, although sounding simple, requires a lot of planning and extra software products to accomplish. Without clustering software and storage replication, the switchover in case of a failure will be quite chaotic.