Date: Fri, 11 May 2007 09:06:31 -0500 From: Eric Anderson <anderson@freebsd.org> To: Bill Moran <wmoran@collaborativefusion.com> Cc: freebsd-performance@freebsd.org, Randy Schultz <schulra@earlham.edu> Subject: Re: possible issues with Dell/Perc5 raid Message-ID: <46447867.3030003@freebsd.org> In-Reply-To: <20070511094217.018c6a2b.wmoran@collaborativefusion.com> References: <Pine.BSF.4.64.0705101545340.34925@tdream.lly.earlham.edu> <20070511094217.018c6a2b.wmoran@collaborativefusion.com>
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On 05/11/07 08:42, Bill Moran wrote: > In response to Randy Schultz <schulra@earlham.edu>: > >> Hi there, >> >> We just purchased a Dell 860 with these specifics: >> - dual core pentium 915, 2.8 GHz, 800MHz FSB >> - 2x512 MB 533 MHz DDR2 RAM >> - Dell's SAS/SATA drive controller(which is actually an LSILogic) >> - their 5IR PCI-Express internal RAID controller >> - a pair of 250 GB SATA II's set up RAID 1 >> >> After installing 6.2-RELEASE on the system I noticed, while pulling the ports >> collection off the CDROM, that the speed to the drives started out just fine >> but long before the ports collection was installed the transfer rate was down >> to ~35kB/s. Huh. So I started paying closer attention. I installed a couple >> of ports and every time there was anything but miniscule data being >> transferred to/from disk the transfer rate bottomed out. I installed the >> blogbench port and it confirmed the I/O as tremendously sluggish. I've >> attached the output of the blogbench runs. The first is from an old 700 MHz >> pc, Acer M25C mobo, with 1 IDE drive just for comparison. The second data set >> is the new Dell. I've also attached the output of dmesg. Everything looks >> fine except for the mpt lines. Would those be telling of something amiss or >> are they innocuous barks? >> >> I understand that RAID 1 is not the fastest but I certainly expected it to be >> faster than it is, esp. with hw RAID. Are my expectations too high and this >> is normal? > > My personal server is a Dell 860 configured very similarly to yours, > with the difference that it has a single 160G SATA drive (no RAID). > It's also running 6.2. > > Frequency = 10 secs > Scratch dir = [/home/wmoran/blogbench] > Spawning 3 writers... > Spawning 1 rewriters... > Spawning 5 commenters... > Spawning 100 readers... > Benchmarking for 30 iterations. > The test will run during 5 minutes. > [..snip..] > Final score for writes: 157 > Final score for reads : 6648 > > For comparison, here are the scores you posted: > > Frequency = 10 secs > Scratch dir = [/var/tmp] > Spawning 3 writers... > Spawning 1 rewriters... > Spawning 5 commenters... > Spawning 100 readers... > Benchmarking for 30 iterations. > The test will run during 5 minutes. > [..snip..] > Final score for writes: 21 > Final score for reads : 2442 > > Certainly looks like that RAID card sucks. Unfortunately, I don't know > what those mpt0 alerts are about. > Could this be a write-through vs write-back cache option difference on the controller? Eric
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