Asking for assistance in determining storage requirements

I have question regarding disk storage for postgres servers

 

We are thinking long term about scalable storage and performance and would like some advise
or feedback about what other people are using.

 

We would like to get as much performance from our file systems as possible.

 

We use ibm 3650 quad processor with onboard SAS controller ( 3GB/Sec) with 15,000rpm drives.

We use raid 1 for the centos operating system and the wal archive logs.

The postgres database is on 5 drives configured as raid 5 with a global hot spare.

 

We are curious about using SAN with fiber channel hba and if anyone else uses this technology.

We would also like to know if people have preference to the level of raid with/out striping.