[Bioclusters] Urgent advice on RAID design requested

[martin goodson]

I'd like to ask for some advice on the design of a new storage system:

We are looking to buy a basic SAN storage system with ~ 4 TB usable
capacity. Our total budget is £15,000 (~$25,000?). The filesystem is for
bioinformatics computational work including a fair amount of database access
but also typical bioinformatics flat file access (>1Gb files).

We would like good performance but really reliability is the number one
issue. The SAN would be in use day and night by a 60 node cluster so I guess
we would be looking at enterprise level reliability if not 24/7 (is there a
difference?). We plan to attach 4 servers to the SAN which all would be
linux intel/AMD. 

We have been using RAID5 SATA with an adaptec fs4500 box with really bad
experiences so we would really like to get this right. (We have had problems
with the controller as well drives failing during RAID5 rebuild.) Good
hardware monitoring would be a must. The controller and basically the whole
system must be really well supported, especially in Linux. Our sysadmin is
really overloaded and would prefer something that does not suck up all her
time in maintenance and configuration.

Just to be perfectly clear, our priorities are reliability >>> size >
performance.

We already have a quote from HP for a SCSI Modular Storage Array with SAN
Switch 2Gbit/8 port BASE SAN KIT.
Is this a reasonable setup. Does anyone have any experience with this kit or
can suggest alternatives? 
Is SCSI over-specifying? Are enterprise SATA drives / controllers /systems
now up to scratch? Should we be using RAID6 or RAID10?

We would really really appreciate some help here.

Thanks in advance,

Martin Goodson
Functional Genetics Unit
Oxford University