what are segmentation faults ? my racksapce linux server had a segmentation fault back on Nov 8, 2000. I rang support and when i said my server returned segmentation faults messages when i tried to telnet into my server to run the 'top' command, the tech guy said could he call me back later he had to check on something.

When he rang back a few hours later he said it was fixed and he had to remount the cpu.

Now today while i was backing up my forum's mysql database i checked the top command and it returned the same message 'segmentation fault' ?

what is it and why does it happen ?

i noticed 3 days ago, my server had been rebooted at rackspace's end ?

should i be requesting to be moved to another server ? I am worried about my data on my server, especially my MySQL databases which hold 5 months of data - over 60MB of forum files.

thanks :)

Segmentation faults occur when a program tries to access memory outside what it has been assigned. It's memory protection in UNIX at work.

It can also occur when a system is running low on memory. Many programs don't bother to check if they actually got the memory they requested. So, when the program tries to access memory it thinks it got - but didn't - boom, seg fault.

I would have the server admins check to see that enough RAM/swap is available on the server.

Kinda like the MSBSoD (Microsoft Blue Screen of Death), without the blue screen :)

Yeah, and without the whole machine going down in flames with it. :)

thanks travis for the reply.

my server is a AMD K6/2 500 with 384MB ram and a 128MB swap file at 3% used

the whole server runs fine except for alot slower not sure if that's cause of the severed net link to the US from Australia or from the segmentation fault.

The bad thing about window is that a blue screen gives you the bad news: you will lose all unsaved information.
Unix just kills the violating program while others stay unaffected.

eva2000:

Offhand, that sounds like plenty of RAM and swap. You might try typing "free" from the shell to check your stats.

A segmentation fault will not cause the server to slow down. If there is some other underlying problem, though, then that could.

well typing 'free' worked

total used free shared buffers cached
Mem: 387440 383548 3892 71512 142808 188744
-/+ buffers/cache: 51996 335444
Swap: 136512 3452 133060

Looks fine on that count... you're not running out of memory.

well they said that my process table was maxed out and caused the segmentation error, rebooting the server fixed it ?

is it cpu upgrade time ?

Originally posted by eva2000.com
well they said that my process table was maxed out and caused the segmentation error, rebooting the server fixed it ?

is it cpu upgrade time ?

Or change your forum software?

i am using vBulletin 1.1.4 :)

Originally posted by eva2000.com
i am using vBulletin 1.1.4 :)

Exactly :)

A cpu upgrade won't fix the problem. But a kernel build could if you modify certain files.

Perhaps someone here can tell me what some of these programs are that are runnin on my server:
6 root -20 -20 0 0 0 SW< 0 0.0 0.6 0:00 caspd
619 root 0 0 800 800 584 S 0 0.0 0.6 0:00 caspd
620 root 0 0 800 800 584 S 0 0.0 0.6 0:00 caspd
622 root 0 0 5196 5196 2816 S 0 0.0 4.0 0:00 caspeng
664 root 0 0 5196 5196 2816 S 0 0.0 4.0 0:00 caspeng
665 root 0 0 5196 5196 2816 S 0 0.0 4.0 0:00 caspeng
666 root 0 0 5196 5196 2816 S 0 0.0 4.0 0:00 caspeng
668 root 0 0 5196 5196 2816 S 0 0.0 4.0 0:00 caspeng


I know Im running on swap space almost all the time, and thats because Im running mysql and the server on the same server with only 128mb ram, but so far so good, nothings crashing, nothings slowing down, but I do notice that whatever caspeng is, there are multiple instances of it and it seems to be the most memory intensive since it has like 7 process's of it running, and it's taking up 4.0 percent of memory for each process, so thats a total of 35% of the servers memory, which seems to me to be a lot, but hey, what do I know. What exactly is caspeng, and why are theire 4 process's of it running, and god forbid I should get some real traffic to my server, when each httpd process is taking like 5.7 to 8.0% of memory.

So, what exactly is caspeng?

Thanks
Bbox

brainbox, from what I found caspd and caspeng are part of Chili!Soft ASP.

Thanks, I don't even have ASP running on my server, as I dont have any hostees that desire it. I wonder how to turn it off, My only fear here is actually getting say 50 clients on the server and having it go kabam from memory overload. I'll have to check that out and see if theres a way to turn those process's off until such a time as a client actually wants to use ASP,
Thanks.,
Bbox

After effect:

Yup, thats what it was, apparently when I first got the server I was fooling around checking things out, and started up the ASP engine, then never shut it down, even though I dont have the Asp checkmarked as being available in the control panel, apparently it configured itself when I first started it up, to restart with the server, until I told it to shut down. So anyway, now theres a heck of a lot more memory freedup, makes me feel a wee bit better.
Thanks for the info.


[Edited by brainbox on 11-23-2000 at 12:24 AM]

There is a nice page here about sig11.
http://www.bitwizard.nl/sig11/

However most likely you just ran out of memory. You should probably have and rlimit on the amount of memory apache can use per process. Check out the Rlimit directives on apache.org


Nick
(cpanel3 developer)

Amd processors are not the best at handling things like CGI and other processor extensive programs, I would suggest a processor upgrade.

cbaker17: I don't know about you, but I swear by the athlon chips. The k6-2/k6-3 chips were not very decent, however I only use athlons for the cpanel.net build servers because I have found them to be the speediest/most reliable for the price.

Weve used athlon processors before and if you keep them properly cooled their ok but nothing beats the stab. of a p3 exp in a 1u case