Try a restart; amongst other things this could be related to memory (error - do a memory test), page file (disk write error - disk check) or task problems (help the scientists).
I have personally seen run-away task failures many times, for many projects - usually immediate failures. I found that a restart was a quick fix even if it did re-occur at a later time. Be sure to keep crunching other tasks!

http://en.wikipedia.org/wiki/SIGSEGV

Just restarted boinc-client, will check the new results. I don't really believe in the magic of turning things off and then on again, though :) Updating boinc-client sounds more promising. I'll try to find an up-to-date deb package for Ubuntu if restarting doesn't help.

I can't see anything worrying in the logs. But then again, I'm only a newbie when it concerns Boinc and grid computing in general :)

31-May-2011 15:15:24 [---] Starting BOINC client version 6.10.17 for x86_64-pc-linux-gnu
31-May-2011 15:15:24 [---] log flags: file_xfer, sched_ops, task
31-May-2011 15:15:24 [---] Libraries: libcurl/7.19.7 OpenSSL/0.9.8k zlib/1.2.3.3 libidn/1.15
31-May-2011 15:15:24 [---] Data directory: /var/lib/boinc-client
31-May-2011 15:15:24 [---] Processor: 16 GenuineIntel Intel(R) Xeon(R) CPU           E5540  @ 2.53GHz [Family 6 Model 26 Stepping 5]
31-May-2011 15:15:24 [---] Processor: 8.00 MB cache
31-May-2011 15:15:24 [---] Processor features: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vm
31-May-2011 15:15:24 [---] OS: Linux: 2.6.32-31-server
31-May-2011 15:15:24 [---] Memory: 11.75 GB physical, 34.43 GB virtual
31-May-2011 15:15:24 [---] Disk: 3.55 TB total, 610.50 GB free
31-May-2011 15:15:24 [---] Local time is UTC +4 hours
31-May-2011 15:15:24 [---] No usable GPUs found
31-May-2011 15:15:24 [---] Not using a proxy
31-May-2011 15:15:24 [World Community Grid] URL http://www.worldcommunitygrid.org/; Computer ID 1607390; resource share 100
31-May-2011 15:15:24 [climateprediction.net] URL http://climateprediction.net/; Computer ID 1151942; resource share 100
31-May-2011 15:15:24 [climateprediction.net] General prefs: from climateprediction.net (last modified 30-May-2011 17:25:05)
31-May-2011 15:15:24 [climateprediction.net] Host location: none
31-May-2011 15:15:24 [climateprediction.net] General prefs: using your defaults
31-May-2011 15:15:24 [---] Reading preferences override file
31-May-2011 15:15:24 [---] Preferences limit memory usage when active to 6017.18MB
31-May-2011 15:15:24 [---] Preferences limit memory usage when idle to 10830.92MB
31-May-2011 15:15:24 [---] Preferences limit disk usage to 50.00GB
BOINC initialization completed, beginning process execution...

Nor there's anything wrong with c4cw tasks:

31-May-2011 07:37:41 [World Community Grid] Computation for task c4cw_target04_001676121_0 finished
31-May-2011 07:37:41 [World Community Grid] Starting c4cw_target04_001688382_0
31-May-2011 07:37:41 [World Community Grid] Starting task c4cw_target04_001688382_0 using c4cw version 641
31-May-2011 07:37:42 [World Community Grid] Computation for task c4cw_target04_001672908_0 finished
31-May-2011 07:37:43 [World Community Grid] Started upload of c4cw_target04_001676121_0_0
31-May-2011 07:37:43 [World Community Grid] Computation for task c4cw_target04_001673135_0 finished

Will be back with more info later. Thanks!

AFAIK, the official Lucid repository only has 6.10.17: https://launchpad.net/ubuntu/lucid/amd64/boinc-client

I have downloaded 6.10.58 from getdeb.net. Still weighing advantages and downsides of having third-party packages :)

Don't want to disappoint anyone, but the magic works as expected :), that is, the client keeps segfaulting after restart. I would not totally dismiss hardware problems, but it doesn't seem likely. Until last week, MySQL was working on this server without a single failure.

I've just installed a newer version of boinc-client, 6.10.58.

Could be one or the other library dependency. I'm running 64 bit Linux (Natty) with the mentioned 6.10.59, and under Maverick when C4CW launched in 64 bit, not had issue either... no one seems to. Think the techs test on 10.04 LTS, one of several flavors of Ubuntu they've got around.

BTW, tried allowing just a single Clean Water and the rest on other WCG sciences? Just curious with 16 cores in your device.

quote
Is this inferring that MySQL is now failing too, when C4CW runs concurrent, or just that you haven't run it since last week?

You could indulge in a test: SIMAP has a 64 bit version of their app and that ran fine too on mine under Lucid LTS. They've got work this week. They are one of a few that are me backup projects if WCG goes off the air for longer and caches run dry... cant have an idle cruncher :D

Let us know

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