Am 15.12.2010 19:37, schrieb Dave Brodin: > Thanks to everyone for suggestions about the load issue. I will > endeavor to provide more specific information. It took a while to move > everything off of that server so I could do the load testing with > smtp-source. Let me preface by saying that my real systems > administrator took another job, so I am filling in. Unfortunately, I am > not proficient with commands to analyze disk and memory performance. I > ran iostat, but I'm not sure how to interpret the results.
Thanks for pasting the material. Post a snippet (perhaps ~20 lines if figures are somewhat consistent within a scenario) of either scenario, and be sure to paste the column headers that iostat output starts with. > last pid: 3429; load averages: 1.85, 0.44, 0.16 up 6+04:33:18 > 13:17:44 > 84 processes: 13 running, 71 sleeping > CPU: 1.9% user, 0.0% nice, 98.1% system, 0.0% interrupt, 0.0% idle This means most time is spent in the kernel. Are you using ZFS? I've seen reports fly by that ZFS was bogging computers down. > Mem: 171M Active, 6548M Inact, 842M Wired, 246M Cache, 827M Buf, 104M Free > Swap: 4096M Total, 60K Used, 4096M Free > > PID USERNAME THR PRI NICE SIZE RES STATE C TIME WCPU > COMMAND > 3350 postfix 1 100 0 37580K 5572K RUN 4 0:08 25.32% > smtpd > 3353 postfix 1 100 0 37580K 5572K RUN 7 0:08 25.31% > smtpd > 3351 postfix 1 20 0 37580K 5572K lockf 3 0:07 23.97% > smtpd > 3354 postfix 1 99 0 37580K 5572K CPU1 7 0:07 23.97% > > [root] iostat 10 > tty mfid0 mfid1 cpu > tin tout KB/t tps MB/s KB/t tps MB/s us ni sy in id > 0 119 28.15 7 0.20 95.44 6 0.58 57 0 0 0 43 > 0 18 6.67 0 0.00 0.00 0 0.00 0 0 0 0 100 > 0 6 0.00 0 0.00 0.00 0 0.00 0 0 0 0 100 > 0 39 12.98 32 0.40 12.89 1 0.01 2 0 81 0 16 > 0 38 12.55 31 0.38 0.00 0 0.00 2 0 98 0 0 > 0 41 12.93 31 0.39 40.91 1 0.04 2 0 98 0 0 > 0 40 13.27 35 0.45 32.00 0 0.02 2 0 98 0 0 > 0 42 12.79 31 0.39 16.00 12 0.19 2 0 98 0 0 > 0 46 12.55 29 0.36 40.17 1 0.05 2 0 90 0 8 > 0 6 16.86 7 0.12 43.78 2 0.08 3 0 22 0 75 > 0 6 19.33 1 0.01 0.00 0 0.00 3 0 22 0 75 > 0 6 0.00 0 0.00 85.40 3 0.25 3 0 22 0 75 > 0 6 15.85 8 0.12 19.82 13 0.25 3 0 23 0 74 > 0 276 6.67 0 0.00 0.00 0 0.00 2 0 12 0 86 > 0 6 0.00 0 0.00 16.00 0 0.00 0 0 0 0 100 > > Not sure if that is going to be helpful. I'm trying to read through > some unix books to get more up to speed on troubleshooting i/o issues. tps means transactions per second (how many operations, more or less), KB/t shows how bit these transactions are on average. We can state that there is little I/O going on, MB/s is consistently < 1, and the tps count is low. > We recently went to using mbx format files in user home directories. So > the mail is delivered first to dmail, which then puts it in the files. > I wasn't involved in this decision, but it seems to be working find on > our current server. I'll have to research maildirs to see if that makes > more sense. I think we should first figure out why your software is spending so much time in kernel space. -- Matthias Andree
