Symlink vs. Mountpoint Performance ?
 

I'm setting up a server cluster using RHEL5. It's a two-node cluster for servering web content. I'll be pointing by Apache configuration to a shared /web directory that is served via NFS by a Network Appliance NAS device.

I'm interested in the performance considerations in choosing to create a separate /web mountpoint in my server's local filesystem using /etc/fstab vs. creating a /netapp mountpoint and then creating a /web symlink that would point to /netapp/web.

Keep in mind that both cluster nodes will need to have access to the content within /web for redundancy during a cluster node failover.

Does anyone out there have any advice for me on this?

Thanks!

symlinks will not give anything notable in terms of a performance hit, but you've not said why you would want to do this... seems totally arbitrary to me. I don't understand the reasons for this apparent separation. Maybe you want to look at a bind mount for multiple mount points rather than a symlink??

A bind mount point won't really get me what I need. I have to have a /web directory due to the custom application that was created to run on this cluster (the app code isn't mine) but there will still be other shares from the NetApp NAS device also... such as /home which will point to /netapp/home via either symlink or mount point.

I'm migrating from an old non-clustered configuration that I didn't set up to a new cluster which I am setting up, and I've been told that the choice of mount point vs. symlink was due to some filesystem backup considerations at the time. Those are going away too.

There will be a considerable amount of disk I/O to the /web directory, which is what raised the question of any known performance benefit of symlink vs. mount point.

This is my first experience with this sort of configuration, so it's not inconceivable that I've gotten myself completely confused over this detail either.

Thanks!