8.04 super slow on dell 2550

[Jason Joines]

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 <joines at 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 at 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
===========