what is sufficient free memory?

["Erik Peter P. Abella" <beyonder@centinet.com>]

Hello All,

I had problems with the RAM (128MB SDRAM DIMM) of my server and the only
spare I had was (64MB SDRAM DIMM).

Hear is what top says:

70 processes: 69 sleeping, 1 running, 0 zombie, 0 stopped
CPU states:  0.1% user,  0.7% system,  0.0% nice, 99.0% idle
Mem:   63124K av,  61296K used,   1828K free,  36880K shrd,   7712K buff
Swap: 104380K av,   3128K used, 101252K free                 35860K
cached

I'm a little worried that the harddisk might thrash as there's hardly
any more memory to spare (1828K free). This server is pretty much an
"all-in-one" box running DNS, squid, postfix, apache and radius (I have
17 modems on it's cyclades). Any recommendations on the "bare-minimum"
RAM for this configuration? The suits at our purchasing division are
"stiff" at best so when I make the requesition for the replacement, I
need to know if I need to "demand" that they "immediately" cough-up the
128mb (or more).


Thanks in advance,


Erik