Best filesystem for PostgreSQL Database Cluster under Linux

Greetings to one and all,

    I've been trying to find some information on selecting an optimal
filesystem setup for a volume that will only contain a PostgreSQL Database
Cluster under Linux. Searching through the mailing list archive showed some
promising statistics on the various filesystems available to Linux, ranging
from ext2 through reiserfs and xfs.

    I have come to understand that PostgreSQLs Write Ahead Logging (WAL)
performs a lot of the journal functionality provided by the majoirty of
contemporary filesystems and that having both WAL and filesystem journalling
can degrade performance.

    Could anyone point me in the right direction so that I can read up some
more on this issue to discern which filesystem to choose and how to tune
both the FS and PostgreSQL so that they can compliment each other? I've
attempted to find this information via the FAQ, Google and the mailing list
archives but have lucked out for the moment.

    Regards,

        Pete de Zwart.