Filesystem setup on new system

Hi list,

I'm helping a customer with their new postgresql server and have some
questions.

The servers is connected to a SAN with dual raid cards which all have
512MB cache with BBU.

The configuration they set up is now.
2 SAS 15K drives in RAID 1 on the internal controller for OS.

6 SAS 15K drives in RAID 10 on one of the SAN controllers for database

10 SATA 10K drives in RAID 5 on the second SAN controller for file
storage.

My first idea was to have one partition on the RAID 10 using ext3 with
data=writeback, noatime as mount options.

But I wonder if I should have 2 partitions on the RAID 10 one for the
PGDATA dir using ext3 and one partition for XLOGS using ext2.

Should I do this instead? Is there just a minor speed bump as the
partitions are on the same channel or?

If this is the way to go how should it be configured?

How big should the xlog partition be?

How should the fstab look like for the XLOG partition?

Any other pointers, hints would be appreciated.

Cheers,
Henke