>> Hi Alan, I think it was your advice I took a long time ago when I >> stopped installing new machines with a swap partition and disabled it >> on my already-installed machines. Some time later, others on this >> list caught wind of what I'd done and told me I was an idiot. Is >> there a consensus on this? If the drawbacks and advantages of using >> swap cancel each other out, I won't use it. > > I think it's basically like this: > > No swap = If you run out of memory, OOM-killer starts killing things > "randomly" and stuff breaks. > > With Swap = System does not run out of memory, so things don't die, > but it runs poetntially much slower during that period of high memory > usage depending on your disk speed and how heavily it is leaning on > swap at that moment (if it is actively trying to use more data in RAM > than you physically have RAM for, it's a total slowdown disaster). If > it's a case of run-away memory usage, it'll run out of swap, too, > anyway, so having swap in that case only delays the OOM-killer. > > I think if you have 4GB of RAM you shouldn't need any swap under > normal circumstances. I have a gentoo box with just 256MB of RAM > that's running web server (apache + php), mail server (postfix + > dovecot), and database (mariadb), and it works fine if i disable swap. > I do normally have swap enabled on it, though, because emerging > sometimes uses a lot of RAM.
Thanks Paul. I'm leaning toward leaving swap disabled. So I'm sure I have the concept right, is adding a 1GB swap partition functionally identical to adding 1GB RAM with regard to the potential for out-of-memory conditions? - Grant
