On Mon, Nov 29, 2010 at 10:50:33PM -0600, Stan Hoeppner wrote: > Dave Chinner put forth on 11/29/2010 10:29 PM: > > On Sun, Nov 28, 2010 at 11:41:35PM -0600, Stan Hoeppner wrote: > >> Yclept Nemo put forth on 11/28/2010 9:57 PM: > >>> You mention an eight-core machine (8c?). Since I operate a dual-core > >>> system, would it make sense to increase my AG count slightly, to five > >>> or six? > >> > >> Dave didn't mention the disk configuration of his "workstation". I'm > >> guessing he's got a local RAID setup with 8-16 drives. > > > > 2 SSDs in RAID0. > > From an IOPs and throughput perspective, very similar to my guess. > Curious, are those Intel, OCZ, or other SSDs? Which model, > specifically? Benchmark data? I ask as all the results I find on the > web for SSDs are from Windows 7 machines. :( I like to see some Linux > results. Cheap as it gets 120GB Sandforce 1200 drives. In RAID0, I'm getting about 450MB/s sequential write, a little more for read. I'm seeing up to 12-14k random 4k writes per drive through XFS. Other than that I didn't bother with any more benchmarks because it was clearly Fast Enough. > > And to point out the not-so-obvious, this is the _default layout_ > > that mkfs.xfs in the debian squeeze installer came up with. IOWs, > > mkfs.xfs did exactly what I wanted without me having to tweak > > _anything_. > > Forgive me for I've not looked at the code. How exactly does mkfs.xfs > determine the AG count? If you'd had a single 7.2k SATA drive instead > of 2 RAID0 SSDs, would it have still given you 16 AGs? If so, I'd say > that's a bug. No, it detected the RAID configuration. 16 AGs is the default for a RAID device, 4 AGs is used if RAID is not detected. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
