According to this kernel bug http://bugzilla.kernel.org/show_bug.cgi?id=11120
it is due to a change implemented there. I did not look at the source in Ubuntu, but would anticipate that it is not changed since most adapter firmware can handle the load with the new setting. I would concur with Sebastien to verify the adapter firmware is up to date as I would hope that Dell would fix it. JP On 04/30/2009 11:22 AM, Sebastien Estienne wrote: > Have you applied all the firmware upgrade to this server BIOS + raid > controller? > > Sebastien Estienne > > > > On Thu, Apr 30, 2009 at 17:16, Jason Joines <joi...@as.okstate.edu> wrote: >> Sebastien Estienne wrote: >>> try benchmarking with a jaunty live cd mounting you hardy partition so >>> you can test a newer kernel >>> >>> -- >>> Sebastien E. >>> >>> >>> Le 27 avr. 09 à 20:15, Jason Joines <joi...@as.okstate.edu> a écrit : >>> >>>> I have a dell 2550 server that I want to get Ubuntu on. I >>>> tried a >>>> few months ago with the initial 8.04 release and the install was so >>>> slow >>>> I gave up. I had tried the mini.iso cd, desktop cd, server cd, and >>>> alternate cd with the same results. >>>> >>>> Recently I decided to try again with the 8.04.2 media and just >>>> let >>>> it keep running. Instead of assuming it had timed out I would go >>>> check >>>> on it once a day and after many days it was finally installed. As an >>>> example of the slow install, when using the text install and at the >>>> point where the dialog said "Installing the base system" it took 66 >>>> minutes to go from a 33% status to a 39% status. Also, by watching >>>> logs >>>> it seemed that the package retrieval from the internet was really fast >>>> but it became super slow any time it was "unpacking". >>>> >>>> The system has a broadcom1 Gbps nic, two pentium III 933 cpu's, 1 >>>> GB of RAM, three 74 GB u160 scsi drives configured as raid 0 via the >>>> builtin dell raid controller which is using the aacraid module. I've >>>> tried both ext3 and xfs as the filesystem. >>>> >>>> This system was running windows server 2k3 and wasn't noticeably >>>> slow. I also have an identical system that is running Ubuntu 7.10 and >>>> it seems to be over three times as fast via these simple tests: >>>> >>>> 7.10 System running 2.6.22 kernel >>>> dd if=/dev/zero of=gigfile00 bs=1k count=1048576 >>>> 1048576+0 records in >>>> 1048576+0 records out >>>> 1073741824 bytes (1.1 GB) copied, 29.5587 seconds, 36.3 MB/s >>>> >>>> dd if=/dev/zero of=gigfile00 bs=1M count=1024 >>>> 1024+0 records in >>>> 1024+0 records out >>>> 1073741824 bytes (1.1 GB) copied, 29.1349 seconds, 36.9 MB/s >>>> >>>> 8.04.2 System running 2.6.24 kernel >>>> dd if=/dev/zero of=gigfile00 bs=1M count=1024 >>>> 1024+0 records in >>>> 1024+0 records out >>>> 1073741824 bytes (1.1 GB) copied, 98.4516 s, 10.9 MB/s >>>> >>>> dd if=/dev/zero of=gigfile00 bs=1k count=1048576 >>>> 1048576+0 records in >>>> 1048576+0 records out >>>> 1073741824 bytes (1.1 GB) copied, 93.9246 s, 11.4 MB/s >>>> >>>> >>>> I found this bug report >>>> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/249964 about >>>> these >>>> smp systems having the aacraid driver hang under high load. However, >>>> this box isn't under any load and I haven't had any of the log >>>> messages >>>> reported. I decided to try the fix anyway so I recompiled the kernel >>>> after changing: >>>> #define AAC_MAX_32BIT_SGBCOUNT ((unsigned short)256) >>>> to >>>> #define AAC_MAX_32BIT_SGBCOUNT ((unsigned short)127) >>>> in aacraid. It didn't help. >>>> >>>> I also tried disabling smp via "maxcpus=1" in grub. It did >>>> disable >>>> smp but it didn't help. >>>> >>>> Any suggestions? >>>> >>>> >>>> Jason Joines >>>> ================================= >>>> >>>> >>>> >>>> -- >>>> ubuntu-server mailing list >>>> ubuntu-server@lists.ubuntu.com >>>> https://lists.ubuntu.com/mailman/listinfo/ubuntu-server >>>> More info: https://wiki.ubuntu.com/ServerTeam >> >> I booted from a 9.04 cd and ran dd from the installer shell. The >> kerenel was 2.6.28. I got the same results as far as speed is >> concerned. However, I was eventually able to generate the errors and >> hang reported by others in the bug report: >> >> aacraid: Host adapter abort request (2,0,0,0) >> aacraid: Host adapt reset request. SCSI hang? >> >> Is this a vanilla kernel bug or Ubuntu specific? I need to get >> this box up and running so if another distribution doesn't have the bug >> I could change. >> >> >> Jason >> =========== >> >> >> -- >> ubuntu-server mailing list >> ubuntu-server@lists.ubuntu.com >> https://lists.ubuntu.com/mailman/listinfo/ubuntu-server >> More info: https://wiki.ubuntu.com/ServerTeam > -- ubuntu-server mailing list ubuntu-server@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-server More info: https://wiki.ubuntu.com/ServerTeam