On 2009-09-04 at 12:27 -0700, [email protected] wrote: > for historical reasons (since it used to be the limit on swap partition > size), I have fallen in the habit of creating a 2G swap partition on all > my systems. If I was going to change it I would probably shrink it down > (by the time a system is using 512M to 1G of swap, it's probably slowed to > unusuable levels anyway and so I would just as soon have the system crash > so that my clustering HA solution can kick in instead)
While I mostly agree about the limited utility of swap, on FreeBSD I still went (go, on my personal box) for swap >= RAM for one simple reason: kernel crash dumps. If you want to be able to figure out *why* a kernel has fubar'd, it's good to be able to get a crash dump and since the swap partition is used for writing that out, you need enough swap to hold the contents of RAM. I've debugged a few issues this way. Given the tendency of the awkward problems to only show up in production systems, no matter *how* good your staging and load test environments, I'd be very loath to give it up. I tend to peruse Linux Weekly News to keep vaguely up-to-date on what's going on in Linux kernel work and I understand that there's a project working on Linux kernel crash dumps too. A search engine yielded: http://lkcd.sourceforge.net/ So, given that you're unlikely to be using all the disk on the systems, it might be worth creating the swap partition, even if you don't enable it now, so that two years from now you don't need to sort out re-partitioning across your cluster so that you can get the dumps to debug the strange problem that keeps killing nodes. Regards, -Phil _______________________________________________ Tech mailing list [email protected] http://lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
