I am using 64bit CentOS 5.5
I know it's possible to set up software RAID1 using mdadm using a physical hard disk and a RAM disk.
Is it possible to set up software RAID1 with mdadm using a NFS mount and a RAM disk instead?
Or another way to put the question, is it possible for a NFS mount to be a block device that works with mdadm?
I plan to use the --write-mostly option so that the reads are done from the RAM disk.
OK, here's the why.
I need a synchronous shared filesystem for my web cluster as Apache is performing writes.
I have tried GlusterFS but the peformance on dynamic pages that require many small files to be read is unacceptable. It takes 5 seconds to create one of the dynamic signup pages on my site for example. It's my understanding that small file performance is a problem with any shared/clustered filesystem to varying degrees. Correct me if I'm wrong.
Since nothing is going to be faster than RAM, hence the question about software RAID1 using a ram drive and a NFS mount.
This way, I'll get the speed of RAM and the synchronous replication I need on the writes.