From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Segitz Subject: Re: Performance of a software raid 5 Date: Sun, 26 Apr 2009 19:03:41 +0200 Message-ID: References: <49ED096E.1000002@anonymous.org.uk> <49ED18E6.1090301@anonymous.org.uk> <15c92f8bd27d912e292c013fea2467e4.squirrel@neil.brown.name> <18925.23969.113047.133385@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <18925.23969.113047.133385@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Tue, Apr 21, 2009 at 7:46 AM, Neil Brown wrote: > I suspect you will see that improve when you add another drive that it > isn't running degraded. Well, i didn't but it doesn't really matter since the crypto layer slows it down to a crawl Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md6 : active raid5 sdd1[0] sdc1[1] md7[3] md8[4] sde1[2] 3907039232 blocks level 5, 256k chunk, algorithm 2 [5/5] [UUUUU] bitmap: 1/15 pages [4KB], 32768KB chunk md7 : active raid0 sdg1[0] sda1[1] 976767744 blocks 128k chunks md8 : active raid0 sdh1[1] sdb1[0] 976767744 blocks 128k chunks So everything is okay now, no missing drive and the bad drive is now gone. for d in /dev/sd[cde]1 /dev/md[678] /dev/mapper/daten bigfile do echo $d dd if=$d of=/dev/null bs=1M count=1000 done /dev/sdc1 1048576000 bytes (1.0 GB) copied, 6.13302 s, 171 MB/s /dev/sdd1 1048576000 bytes (1.0 GB) copied, 12.2261 s, 85.8 MB/s /dev/sde1 1048576000 bytes (1.0 GB) copied, 11.8026 s, 88.8 MB/s /dev/md6 1048576000 bytes (1.0 GB) copied, 6.42977 s, 163 MB/s /dev/md7 1048576000 bytes (1.0 GB) copied, 9.51655 s, 110 MB/s /dev/md8 1048576000 bytes (1.0 GB) copied, 7.97321 s, 132 MB/s /dev/mapper/daten 1048576000 bytes (1.0 GB) copied, 28.6309 s, 36.6 MB/s bigfile 1048576000 bytes (1.0 GB) copied, 31.9715 s, 32.8 MB/s So the raid works okay, although i'm not thrilled by 163 MB/s read speed when i see what the underlying devices are capable of. But the real bad drop seems to be the crypto and with http://tynne.de/linux-crypto-speed in mind it seems quite a reasonable speed, although i'm disappointed since i expected more. Next time i won't expect but do better tests beforehand. Thanks everyone for their help. Johannes