10 Aug
2000
10 Aug
'00
8:37 p.m.
On Thu, Aug 10, 2000 at 12:01:03PM -0500, Jay Orr wrote:
Yes, latency is a big factor, but wasn't the question about directly connected RAID (or a SAN) vs. a filer? Since both are raided, the latency would be roughly equal.
But they're not.
Why?
Mostly, I suspect, because of the journaling. A good journaling filesystem on a locally-attached RAID 5 (or 4, if you get around the performance problems the way NetApp has) disk array with lots of RAM cache for the journal would probably at least match, and likely outstrip the NetApp's performance.
Keep in mind also that the NetApp can play fast-and-loose with it's journal-commits because it's all in NVRAM, so it does not commit before returning success to the client. That HAS to be a big win.
--
Aaron Sherman
Systems Architect
HighWired.com -- The global high school community
http://www.highwired.com
300 North Beacon Street
Watertown, MA 02472
(617) 926-1850 x238
(617) 926-1861 fax
asherman@highwired-inc.com / ICQ#43677395 / Y!ajstrader
"We had some good machines, but they don't work no more."
-"Faded Flowers" / Shriekback