On Wed, Feb 04, 2004 at 02:48:47PM -0600, Justin King wrote:
> 2. Backups over the SAN are slow (the utilization on this SAN is very
> low, roughly 1-2%).  I'd originally had the linux media server setup as
> a client. Over 1Gb Ethernet fiber, I was backing up at around 12MB/s,
> when I moved it to a media server, it dropped to around 6.8MB/s over the
> SAN.  The absolute fastest backup I've ever gotten over the SAN runs
> around 15MB/s.  This (to me) doesn't seem anywhere near peak
> performance.  Anyone have any experience with a similar setup (or
> pointer for performance tuning)?  Ideally, I'd love some kind of
> performance benchmarks I might be able to compare against.

We see performance all over the board.  We've got some cases where
backing up over GigE as a client is faster than backing up directly over
the SAN.  We've got cases were an upgrade from a 100mbps Ethernet
connection to GigE made no difference at all since we simply couldn't
read the data from disk fast enough.

If you've got lots of little files, you're going to pay the price.  Big
files back up a lot more quickly than little files - sometimes by a
factor of 20.

-- 
Ed Wilts, Mounds View, MN, USA
mailto:ewilts AT ewilts DOT org