Kirk Bocek wrote:
Responding to several of your posts here. I understand your need for stability, but can't you set StorSave down and see what it does to your speed?
I could, but I don't see the point. I have one machine with StorSave set at "Protect" which writes at 60MB/Sec. The other identical system which is also set to "Protect" only writes at 20MB/Sec. Therefore, there must be something else at work.
As we speak, I have swapped the hard drives in these two systems and I am running another test. This will at least tell me if the problem is based in the hard drives & OS or elsewhere in hardware.
Some of my 95MB/Sec was achieved with some of the suggested ext3 journal settings. Look back through my previous thread.
Memory interleaving on my system (Supermicro X7DVL-E) is turned on automatically when you install two pairs of memory sticks. With 16GB on your system, I *assume* you have at least 4 sticks. Check the manual and see if there is a BIOS setting.
I found the interleaving settings in the BIOS. Both systems currently have it turned off, so I haven't touched it at this point. Once I have determined why the performance is so different between these two machines, I may experiment with that setting to see if it helps.
Right now, I am not looking for maximum performance. I am just trying to determine why there is a 3x difference in write performance between two identical machines.
A number of people emailed me and asked for the mount options on the device I posted performance numbers for. They are:
/dev/sda1 /data ext3 data=writeback,noatime,defaults 1 2
Cheers,
On Fri, 2006-10-13 at 11:44 -0400, Bowie Bailey wrote:
Kirk Bocek wrote:
<snip>
Right now, I am not looking for maximum performance. I am just trying to determine why there is a 3x difference in write performance between two identical machines.
60 vs. 40 conductor cables on UDMA? have you wiggled/reseated them? PS sizes similar and simailar load? /var/log/messages BogoMips the same? Mem config same?
Same "load". Does top in a "long" screen show any diference in number of loads or total load being imposed? Keep an eye out for excessive wait channels in top (have to change defaults of fields displayed and order) or in ps?
Are you using the sar reports, which can be helpful in the case of large unknowns.
HTH -- Bill
On Fri, 2006-10-13 at 11:44 -0400, Bowie Bailey wrote:
Kirk Bocek wrote:
<snip>
Right now, I am not looking for maximum performance. I am just trying to determine why there is a 3x difference in write performance between two identical machines.
P.S. I know you're not using DMA, I just rattled of some common things I checkfor when seeing discrepancies like this. Seating issues are, after all universal. With SCSI, I always check to be sure active termination (if appropriate) is in place. Bad terminations slow SCSI way down. -- Bill
-
Bowie Bailey -
chrism＠imntv.com -
William L. Maltby