Sorry dont have the answer for you But can you tell me what command you used to see all loads on your node ?
Thanxs Steffan Van: users-boun...@openvz.org [mailto:users-boun...@openvz.org] Namens Rene Dokbua Verzonden: maandag 21 mei 2012 20:07 Aan: users@openvz.org Onderwerp: [Users] occasional high loadavg without any noticeable cpu/memory/io load Hello, I occasionally get this extreme load on one of our VPS servers. It is quite large, 4 full E31230 cores, 4 GB RAM and hosting ca. 400 websites + parked/addon/subdomains. The hardware node has 12 active VPS servers and most of the time things are chugging along just fine, something like this. 1401: 0.00 0.00 0.00 1/23 4561 1402: 0.02 0.05 0.05 1/57 16991 1404: 0.01 0.02 0.00 1/73 18863 1406: 0.07 0.13 0.06 1/39 31189 1407: 0.86 1.03 1.14 1/113 31460 1408: 0.17 0.17 0.18 1/79 32579 1409: 0.00 0.00 0.02 1/77 21784 1410: 0.01 0.02 0.00 1/60 7454 1413: 0.00 0.00 0.00 1/46 18579 1414: 0.00 0.00 0.00 1/41 23812 1415: 0.00 0.00 0.00 1/45 9831 1416: 0.05 0.02 0.00 1/59 11332 12 active The problem VPS is 1407. As you can see below it only uses a bit of the cpu and memory. top - 17:34:12 up 32 days, 12:21, 0 users, load average: 0.78, 0.95, 1.09 Tasks: 102 total, 4 running, 90 sleeping, 0 stopped, 8 zombie Cpu(s): 16.3%us, 2.9%sy, 0.4%ni, 78.5%id, 1.8%wa, 0.0%hi, 0.0%si, 0.1%st Mem: 4194304k total, 2550572k used, 1643732k free, 0k buffers Swap: 8388608k total, 105344k used, 8283264k free, 1793828k cached Also iostat and vmstat shows no particular io or swap activity. Now for the problem. Every once in a while the loadavg of this particular VPS shoots up to like crazy values, 30 or more and it becomes completely sluggish. The odd thing is load goes up for the VPS server, and starts spilling into other VPS serers on the same hardware node - but there are still no particular cpu/memory/io usage going on that I can se. No particular network activity. In this example load has fallen back to around 10 but it was much higher earlier. 16:19:44 up 32 days, 11:19, 3 users, load average: 12.87, 19.11, 18.87 1401: 0.01 0.03 0.00 1/23 2876 1402: 0.00 0.11 0.13 1/57 15334 1404: 0.02 0.20 0.16 1/77 14918 1406: 0.01 0.13 0.10 1/39 29595 1407: 10.95 15.71 15.05 1/128 13950 1408: 0.36 0.52 0.57 1/81 27167 1409: 0.09 0.26 0.43 1/78 17851 1410: 0.09 0.17 0.18 1/61 4344 1413: 0.00 0.03 0.00 1/46 16539 1414: 0.01 0.01 0.00 1/41 22372 1415: 0.00 0.01 0.00 1/45 8404 1416: 0.05 0.10 0.11 1/58 9292 12 active top - 16:20:02 up 32 days, 11:07, 0 users, load average: 9.14, 14.97, 14.82 Tasks: 135 total, 1 running, 122 sleeping, 0 stopped, 12 zombie Cpu(s): 16.3%us, 2.9%sy, 0.4%ni, 78.5%id, 1.8%wa, 0.0%hi, 0.0%si, 0.1%st Mem: 4194304k total, 1173844k used, 3020460k free, 0k buffers Swap: 8388608k total, 115576k used, 8273032k free, 725144k cache Notice how cpu is plenty idle, and only 1/4 of the available memory is being used. http://wiki.openvz.org/Ploop/Why explains "One such property that deserves a special item in this list is file system journal. While journal is a good thing to have, because it helps to maintain file system integrity and improve reboot times (by eliminating fsck in many cases), it is also a bottleneck for containers. If one container will fill up in-memory journal (with lots of small operations leading to file metadata updates, e.g. file truncates), all the other containers I/O will block waiting for the journal to be written to disk. In some extreme cases we saw up to 15 seconds of such blockage.". The problem I noticed last much longer than 15 seconds though - typically 15-30 minutes, then load goes back where it should be. Any suggestions where I could look for the cause of this? It's not like it happens everyday, maybe once or twice per month, but it's enough to cause customers to complain. Regards, Rene
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