Hi, I have seen this too using custom kernels on Hardy and on the current RC of Karmic Koala. The performance regression I have seen using the standard Linux CCISS kernel driver is a drop of about 66% performance. The performance regression was introduced in 2.6.29-rc1 and is in current kernels up to and including 2.6.32-rc5. Since Karmic Koala is based on 2.6.31 is shares the same performance drop when compared with Hardy.
Since Ihave seen mention of Canonical trying to get Ubuntu certified on HP kit, I would expect there to be a vested interest for both Canonical and HP to resolve this problem. I have put detailed performance tests at the following URL to highlight this issue. http://bugzilla.kernel.org/show_bug.cgi?id=13127 In summary using the standard Hardy kernel (2.6.24-24-server) and custom kernels (using the kernel config from 2.6.24-24-server to keep the same options) listed below I see around 90MB/s while reading off a single SAS 146GB 10k RPM drive in a RAID-0 logical drive on a DL360G5 and DL380G5. >From 2.6.29-rc1 through to current kernels I see around 34MB/s while doing the same test. The following give around 90MB/s read of the logical drive: 2.6.24-24-server 26.24.7 2.6.25.20 2.6.26.8 2.6.27.37 2.6.28.10 The following give around 34MB/s read of the same logical drive: 2.6.29-rc1 2.6.29 2.6.29.1 through 2.6.29.6 2.6.30.9 2.6.31.4 2.6.32-rc5 The test I performed on all the above was a simple: dd if=/dev/cciss/c0d1 of=/dev/null bs=1024k count=1024 dd if=/dev/cciss/c0d1 of=/dev/null bs=1024k count=2048 Performance from Hardy: -------------------------- Wed Oct 21 16:40:54 BST 2009 Linux uk-ditnas902 2.6.24-24-server #1 SMP Fri Sep 18 16:47:05 UTC 2009 x86_64 GNU/Linux 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 11.83 s, 90.8 MB/s 2048+0 records in 2048+0 records out 2147483648 bytes (2.1 GB) copied, 23.6072 s, 91.0 MB/s -------------------------- Performance from current Karmic Koala: --------------------- Linux uk-ditnas903 2.6.31-14-server #48-Ubuntu SMP Fri Oct 16 15:07:34 UTC 2009 x86_64 GNU/Linux 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 31.0771 s, 34.6 MB/s ------ 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 31.1101 s, 34.5 MB/s --------------------- ** Bug watch added: Linux Kernel Bug Tracker #13127 http://bugzilla.kernel.org/show_bug.cgi?id=13127 -- HP cciss / SmartArray responding slowly https://bugs.launchpad.net/bugs/337419 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
