Am 11.11.2010 16:40, schrieb David Siebert:
> ZFS has an option to use an SSD as cache for the spinning drives. ZFS
> under Solaris has turned in some really good IO numbers. The problem is
> with the new Sun I am not feeling so good about the open nature of
> Solaris. ZFS performance under BSD I have read does not match ZFS under
> Solaris.
Very true. Also, we experienced (with a 32-core/64GB Sun X4600 machine
and a direct-attached storage array with 24 10k-spindles) that
PostgreSQL scaled *badly* (with the number of active, long-running
queries) when using ZFS. Installing CentOS with XFS, the same hardware
delivered very good scaling and higher absolute performance.
Admitted, this were more or less out-of-the-box configurations (but we
did some tuning with ZFS, which resulted in a 2x speedup - still not
enough). But the difference was drastic. We went with Linux/XFS then.
Joachim