We have reached that point where one application server is not enough. Apart from performance benefits we want to have a somewhat failover scenario as we cannot afford a 30 minute downtime just because the server needs a reboot for the new kernel.
The first issue that has to be resolved is where to store the shared files so that both application servers can access it all the time. Possible solutions are:
- DRBD with NFS on both servers.
- A NAS with NFS
- SAN with a clustered filesystem
We want to keep the solution as simple as possible and we don't want to spend a fortune on it. DRBD synchronization is cheap but too fragile. SANs are expensive and i've heard some horror stories with clustered filesystems. A NAS with NFS seems the best fit.
How do you handle shared storage from multiple servers? Have you encountered any problems with NFS?
Bonus Question: Sun has a start up essentials program that offers significant discounts and we can grab their Sun 7110 Unified Storage for about 6k. Has anyone any experience with unified storage? Are there any fairly priced alternatives ?