On 05/12/17 13:07, Peter Humphrey wrote: >> (My new system when I get it working maxes out at 64GB ram so I'll have >> > 256GB swap and (currently) 16GB ram)
> I've halved my original 4GB swap to 2GB since it never seems to be used. I'm > not brave enough to do away with it altogether though. I've just had a long thread with someone on the SUSE list who refuses to believe that the "twice ram" rule ever existed. This despite someone else actually describing the algorithm (from which one can see where the rule comes from), and me pointing out that (after Linus stripped out all the "awful" optimisation code) the early vanilla 2.4 kernels enforced this rule by crashing if you broke it. Swap was rewritten as a result of that, but I've never heard whether the fundamental algorithm was changed, so I still provision my systems on the assumption it's true. Disk is cheap ... my 4TB drives cost about £110, so that makes 128GB for swap cost, what, £3? I'll probably never need it, but hey, at that price :-) Cheers, Wol