Moving MySQL to SAN

We are moving our databases to an EMC CX320 but we do not have any recommendations on what file system to use on the SAN to support our large databases. We currently use ext3 but it has issues with really large partitions over 2Tb. We also have an issue with finding a file system that supports MySQL's "innodb_flush_method = O_DIRECT". A MySQL support rep suggested using Linux GFS but this seems to entail running the linux cluster software which sounds like overkill. Has anyone run a write and read intensive MySQL database on a SAN and if so have any tips on configuring the filesystem for such a load.
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BigSchmuhConnect With a Mentor Commented:
Why don't you go with "raw device" (see below for MySql 5.0) for large tables and jfs for others ?

A raw device does not require a fs and is directly managed by MySQL (it is even faster than any O_DIRECT option). Of course, you can not backup the raw device directly (offline backup only) but there are MySql Utilities to do that.

Regarding ext3, I read (see below) a complaint about ext3 O_DIRECT fs causing some cpu ticks to be dropped
BigSchmuhConnect With a Mentor Commented:
Next is the SAN usage because every array is designed to better support some block size than others.

Example: A raid 5 array of 10 drives using a 64KB chunk size (=9x64KB full stripe size) will definitely better perform when used by a 64KB block io client than by another io client
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