Gordon Messmer wrote: > On 09/16/2015 09:11 AM, Callum Scott wrote: >> It is running a little >> tight on memory and so there have been a couple of events where the >> OOM_killer has been invoked and killed off MySQL, which you would >> expect. > > One thing that should be noted is that regardless of swappiness, > overcommit might be an issue. If a single process is using most of the > memory in a system, and attempts to fork(), as it will if it calls > system(), then the system may require that there is enough memory for a > second instance of that huge process. > > This is one of the reasons why swap should be as large or larger than > system RAM. <snip> Excerpt on heavy-duty servers. We're certainly not going to allocate hundreds of gigs, or a terabyte or so, for swap. (Yes, we do have servers with that kind of RAM, and that's not counting the small SGI supercomputer....) mark