On 02/10/11 08:25, Eukasz Czarniecki wrote: > Hi > > I've bought a Dell R310 with H200 raid controller reported in dmesg as: > Symbios Logic SAS2008. It uses mpii driver and has two hard drives > configured in RAID 1. ... > Now it seems to work fine but i still have a problem with its > performance. Raid is fully initialized. > > How can I help to resolve this problem? > > I'm doing simple benchmark: > wget ftp.spline.de/pub/OpenBSD/4.8/sys.tar.gz
tip: use OpenBSD's resident ftp app, save a package: /tmp $ ftp http://ftp.spline.de/pub/OpenBSD/4.8/sys.tar.gz (this is about a 20M file), and /tmp $ time tar xzf sys.tar.gz 0m2.69s real 0m0.56s user 0m0.96s system > time tar xzf ./sys.tar.gz > > On the same hardware Linux unpacks it in less then two seconds. > > Numbers for OpenBSD: > 4.8 amd64 sp: 3m40.95s real 0m0.65s user 0m0.71s system > 4.8 amd64 mp-stable: 3m43.36s real 0m0.48s user 0m0.98s system > 4.9 amd64 sp: 3m47.72s real 0m0.51s user 0m0.69s system > 4.9 i386 rd : 3m45.11s real 0m1.03s user 0m1.19s system i.e., "basically the same for all" Therefore, I'm ignoring all but the 4.9 GENERIC. I almost never complain about dmesgs being included, but including four different dmesgs that show the same result wasn't overly interesting and 57k emails are a bit big... :) ... > # bioctl -ivh mpii0 > Volume Status Size Device > mpii0 0 Online 232G RAID1 > 0 Online 233G 0:1.0 noencl <ATA WDC WD2502ABYS-1> > 'WD-WCAT1H125700' > 1 Online 233G 0:0.0 noencl <ATA WDC WD2502ABYS-1> > > 'WD-WCAT1H123678' > # pcidump -v ... Sounds like you don't have softdeps running on your system. Use 'em (FAQ 14). Also, check to see if your RAID card has a battery for its cache, if it doesn't, a lot of RAID controllers drop to non-cached writes, and often seem to slow down way beyond what you'd expect just to make you buy the dang battery :). I believe most of the current crop of Dell RAID controllers have an option buried in the RAID setup screens to cache writes even without a battery. Don't blame me (or Dell, or anyone else) if you trip over the power cord and blow away your array. I think I heard something about some Linux variants pushing the cache back on even without the battery. Linux may also just be caching in local RAM...did you note if the disk lights were out when the command prompt came back? On my system, with a pair of SATA disks in an Accusys mirroring box (which does no write caching, but then, there's no battery option, so it doesn't have an axe to grind with me because I didn't buy it), here's what I got with softdeps: /tmp $ time tar xzf sys.tar.gz 0m2.69s real 0m0.56s user 0m0.96s system With /tmp remounted without softdeps: /tmp $ time tar xzf sys.tar.gz 0m30.90s real 0m0.60s user 0m1.28s system A lot slower, but still a lot better than you are getting, so, I suspect you have both issues going on. There are about 10,000 files in that file, so that's a lot of file creations, that's the stuff that Softdeps shines on. Nick. > > Dmesgs: ... > OpenBSD 4.9-beta (GENERIC) #457: Mon Feb 7 11:56:10 MST 2011 > t...@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC > real mem = 3210317824 (3061MB) > avail mem = 3110871040 (2966MB) ...
