AIX

Sorry, when i do not understand the problem completely.

There are two possible situations: you have a HACMP cluster (lets call the machines A and B) and they have between them some filesystem, which an application uses. HACMP should make sure that this filesystem is exported as an NFS share for some third machine C. Normal operation would be that the FS is mounted on A and exported from there to C, if A fails B should mount the FS and export it to C again.

If this is what you want it is called HA-NFS and is included in standard HACMP since more than a decade (IIRC the first version of HACMP including the up to then standalone feature HA-NFS was 4.2 from 1995 or so). You should simply enter the mounts and the exportfs commands necessary to the Start-/Stop-scripts of the TAKEOVER event in HACMP so they get executed whenever a takeover takes place.

The other possibility is: you have a external machine which exports some filesystem to the cluster nodes and you want to have the active cluster node mount this filesystem.

The first advice is: don't do it. NFS is by no means a device to mount filesystems for a longer time. Since your machine has one and only one IP stack (which NFS is using) your network performance probably will go down when you use the filesystem. NFS is a great tool if you want to quickly distribute data from one system to the other: mount the FS, do whatever you want, umount it. To use it for mounting e.g. filespace for a database or something such is very poor design, regardless of it working or not.

NFS won't be able to reliably remount the FS once the connecction gets temporarily distorted, you can't cleanly "cut the line" to the disks in case something fails (like you could do with SCSI- or FC-AL-devices), etc. If you have a hanging NFS-mount quite often the only way to get rid of it is to reboot the machine. This is NOT a desirable setup.

Having said this it will (with the restrictions mentioned) work quite normally, wenn you include the NFS-shares in a "resource group". See your HACMP documentation on how to manage resource groups and what they consist of. Basically a resource group is a set of filesystems, some Start-/Stop-scripts to start/stop an application, some service IP-adresses, etc. This resource groups will swing back and forth between the cluster nodes when a takeover takes place. An "active" cluster node is basically the node which has the resource group(s) active.

I hope this helps.

bakunin

Can the moderators merge this thread with another HACMP + NFS thread AIX 6.1 and NFS problem after HACMP config

thanks