Running out of swap space????

[Björn König]

pauls at utdallas.edu schrieb:
> I've got a server that is running out of swap space:
> 
> +pid 37308 (mysqld), uid 88, was killed: out of swap space
> +swap_pager: out of swap space
> +swap_pager_getswapspace(1): failed
> 
> The strange this is, this server has a 6GB swap partition!
> 
> swapinfo -h
> Device          1K-blocks     Used    Avail Capacity
> /dev/da0s1b       6291456     2.6G     6.0G    43%
> 
> This isn't exactly a resource-starved machine either:
> 
> CPU: AMD Opteron(tm) Processor 244 (1793.88-MHz K8-class CPU)
>  Origin = "AuthenticAMD"  Id = 0xf5a  Stepping = 10
> 
> Features=0x78bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,MMX,FXSR,S 
> 
> SE,SSE2>
>  AMD Features=0xe0500800<SYSCALL,NX,MMX+,LM,3DNow+,3DNow>
> real memory  = 2146893824 (2047 MB)
> avail memory = 2065797120 (1970 MB)
> ACPI APIC Table: <PTLTD          APIC  >
> FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
> cpu0 (BSP): APIC ID:  0
> cpu1 (AP): APIC ID:  1
> 
> FreeBSD hostname.utdallas.edu 6.0-RELEASE FreeBSD 6.0-RELEASE #0: Thu 
> Mar 30 19:25:18 CST 2006 
> root at hostname.utdallas.edu:/usr/obj/usr/src/sys/SMPKERNEL  amd64
> 
> last pid: 52327;  load averages:  0.45,  0.46,  0.45 up 11+03:42:04  
> 03:32:15
> 63 processes:  1 running, 62 sleeping
> CPU states:  5.3% user,  0.0% nice,  0.8% system,  3.9% interrupt, 90.1% 
> idle
> Mem: 1410M Active, 126M Inact, 190M Wired, 82M Cache, 214M Buf, 78M Free
> Swap: 6144M Total, 2687M Used, 3457M Free, 43% Inuse
> 
> Any suggestions are welcome - what could cause this?

ps aux | sort -n +5

The latter processes need most memory.

> How to 
> troubleshoot?

This may be normal behaviour. It depends on the processes.

> Possible solutions/workarounds?

It depends also. Possible solutions are: Add more RAM, add swap (see 
[1]) or run less processes.

[1] http://www.freebsd.org/handbook/adding-swap-space.html

Regards Björn