Memory

Testing RAM for errors

Memtest86 is thorough, stand alone memory test for x86 architecture computers. It is offered in a ISO image, so that you can put the image on bootable CD.

download memtest

Debugging memory hogs in BSD

To discover which process is using the most memory percentage wise:

# ps aumx | head
USER    PID %CPU %MEM   VSZ  RSS  TT  STAT STARTED      TIME COMMAND
frankk 64873  0.0  7.9 71352 61644  ??  S    11:17PM  20:07.78 /usr/X11R6/lib/firefox/firefox-bin
frankk   607  0.0  7.7 74080 59832  ??  S     4:25PM   6:18.70 /usr/X11R6/lib/thunderbird/thunderbird-bin
frankk   583  0.0  7.0 64728 54568  ??  I     4:25PM  17:46.62 /usr/X11R6/lib/firefox/firefox-bin
root    561  0.8  3.0 152640 23116  v0  R     4:25PM  10:37.38 X :0 -nolisten tcp (Xorg)
frankk   869  0.0  3.7 34332 29036  ??  S     6:10PM   6:13.38 gaim
frankk   611  0.0  1.6 16476 12560  ??  S     4:28PM   1:39.09 xchat
root    678  0.0  0.5  5604 4000  ??  S     4:54PM   0:05.35 xterm (xterm-static)
root    644  0.0  0.5  5512 3916  ??  S     4:35PM   0:14.46 xterm (xterm-static)
root    392  0.0  0.3  3460 2332  ??  Ss    4:24PM   0:01.97 sendmail: accepting connections (sendmail)

Two other columns worth noting:

vsz = virtual size in Kbytes (alias vsize)

rss = resident set size

Lookup "KEYWORDS" in the ps Manual for a list of keys you can display.

swap is also an important part of memory that resides on the disk.