can we get vmstat 1 output for the run? thanks, Alex >>>>> Andrew Morton (AM) writes: AM> Why is ext3 slow?? AM> Begin forwarded message: AM> Date: Tue, 7 Nov 2006 09:47:17 -0500 AM> From: "Bill Rugolsky Jr." <brugolsky@xxxxxxxxxxxxxxxxxxxxxxxxx> AM> To: Arne Schmitz <arne.schmitz@xxxxxxx> AM> Cc: linux-ide-arrays@xxxxxxxxxxxxxxxxx AM> Subject: Re: ICP, 3ware, Areca? AM> On Tue, Nov 07, 2006 at 03:25:04PM +0100, Arne Schmitz wrote: >> Has anyone information about how current ICP and Areca hardware performs under >> Linux? We are currently running kernel 2.6.17 and have two offers, one with >> an Areca ARC-1220 8-port, and one with an ICP 9087MA 8-port. Does either of >> them make trouble running a (64 bit) Linux? >> >> At the moment we only have two 3ware controllers running on 32 bit Linux. AM> On Fri, 18 Aug 2006, I wrote to the list: AM> I've been doing sequential raw disk I/O testing with both Jens Axboe's AM> "fio" using libaio and iodepths up to 32, as well as a basic AM> "dd if=/dev/zero oflag=direct". AM> Reads look fine; a zone read test shows 360 MiB/s at the start of the disk, AM> 190 MiB/s at the end. I see similarly high numbers doing direct reads via AM> ext3. AM> Unfortunately, no matter what I do on the write side, I don't see AM> more than 72 MiB/s for a sequential direct I/O write to the raw disk. AM> I've tried the deadline and noop schedulers, boosted nr_requests and AM> toyed with various i/o sizes and queue depths using fio. I was expecting AM> sequential writes in the range of 120-150 MiB/s, based on the (now AM> ancient) tweakers.net review and various other info. [Copying /dev/zero AM> to tmpfs on this box yields ~860 MiB/s.] AM> The machine is a Tyan 2882 dual Opteron with 8GB RAM and an Areca 1220 AM> / 128MB BBU and 8xWDC WD2500JS-00NCB1 250.1GB 7200 RPM configured as a AM> RAID6 with chunk size 64K. [System volume is on an separate MD RAID1 on AM> the Nvidia controller.] It's running FC4 x86_64 with a custom-built AM> 2.6.17.7 kernel and the arcmsr driver from scsi-misc GIT, which is AM> basically 1.20.0X.13 + fixes. The firmware is V1.41 2006-5-24. AM> Chris Caputo suggested: AM> I'd run a test with write cache on and one with write cache off and AM> compare the results. The difference can be vast and depending on your AM> application it may be okay to run with write cache on. AM> And I reported back on Tue, 22 Aug 2006: AM> Forcing disk write caching on certainly changes the results AM> (and the risk profile, of course). For the archives, here are AM> some simple "dd" and "fio" odirect results. These benchmarks AM> were run with defaults (CFQ scheduler, nr_request = 128). AM> ... AM> Summary: AM> Raw partition: 228 MiB/s AM> XFS: 228 MiB/s AM> Ext3: 139-151 MiB/s AM> Regards, AM> Bill Rugolsky AM> - AM> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in AM> the body of a message to majordomo@xxxxxxxxxxxxxxx AM> More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
