On Tue, 20 Aug 2002, Igor Schein wrote:
On Tue, Aug 20, 2002 at 01:56:08PM -0700, Jeff Bryer wrote:
Not urban legend for us. We've experienced this just last week.
/.../
After reading through responses, I get a feel that
- the alleged Solaris bug only appears with Gb connection involved (
it wasn't clear in the original messages ). I only have 100Mb Suns with 1 exception.
/.../
Hmmm. I've had a "unique" situation, then. The symptoms that I first reported (a year ago? longer?) were peculiar only to Oracle's I/O to the filer, _not_ an issue with NFS per se.
I noticed that under extreme stress, UDP performance on Solaris 7 was topping out around 40,000 packets/sec - a limit in the network stack or in the switch, or in the Gigabit driver? We've switched to TCP and seen some improvement, but the underlying cause is still a mystery. Since our performance is acceptable and we don't have the time/equipment to really do a thorough set of tests to get to the bottom of it, we've decided to ignore it. :-)
We're (still) running 5.3.7R3 on an F760 with six FC9's, two volumes (8x 36GB each) for Oracle on two FC-AL loops, Gigabit-II card; Cisco 3508G switch; Sun E4500, Sbus Gigabit 2.0, Solaris 7 HW11/99+latest patches, driver updates, etc. Using "bonnie" or "cpio" or various other tools to test plain old NFS performance, the E4500 can easily saturate the single PCI bus in the F760, getting write speeds of 35-37MB/sec, read speeds sometimes into the 50MB's range. Our 420R's with PCI Gigabit cards can top it out too. We've never had a problem with typical NFS loads.
Oracle, on the other hand, seems to throttle itself - we typically see a single Oracle (8.1.7.3) I/O slave reading or writing 3-5MB/sec (UDP) or now about 7-8MB/sec (TCP). We've concluded that this is NOT a problem with the filer, or the network - with multiple Oracle I/O procs running on multiple CPUs and doing parititioned table scans, for instance, Oracle *can* saturate the filer. But for small non-partitioned apps where you get no parallelism, Oracle - or its interaction with Solaris - introduces a bottleneck that nobody has been able to identify...
Anyway, we'll hopefully be jumping up to Solaris 8 (or 9) and Oracle 9i and ONTAP 6.x, at which point we might be able to take the time to do some tests and see if newer versions of all the various software bits will make things go faster...
As to the original poster's question, though, our experience with Oracle on the filer has been overwhelmingly positive. I have no hesitation recommending it - subject, of course, to the caveat that you should test your particular application to determine if it's a good fit or not.
-- Chris
-- Chris Lamb, Unix Guy MeasureCast, Inc. 503-241-1469 x247 skeezics@measurecast.com