Date: Sun, 5 Apr 1998 18:07:31 -0500 (EST) From: "John S. Dyson" <dyson@FreeBSD.ORG> To: dswartz@druber.com (Dan Swartzendruber) Cc: dyson@FreeBSD.ORG, dg@root.com, dag-erli@ifi.uio.no, stable@FreeBSD.ORG, current@FreeBSD.ORG Subject: Re: swap-leak in 2.2.5 ? Message-ID: <199804052307.SAA00506@dyson.iquest.net> In-Reply-To: <3.0.5.32.19980405182046.009137d0@mail.kersur.net> from Dan Swartzendruber at "Apr 5, 98 06:20:46 pm"
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Dan Swartzendruber said: > At 04:35 PM 4/5/98 -0500, John S. Dyson wrote: > >Dan Swartzendruber said: > >> > >> My only quibble with this technique is that it would seem to make it > >> harder to tell if your machine is really running low on swap or not > >> (e.g. swap as backing store for stack/heap/whatever *is* critical and > >> allocation failure can cause application failure, whereas swap being > >> used to cache random cruft is in the "who really cares" department). > >> Or is there some way to tell the difference? > >> > >It is difficult not only to tell if you are low on swap, but also it > >is hard to quantify being low on memory. I have been thinking about > >this over the last year or so. > > It was actually kind of embarrassing. I convinced a local ISP to start > converting their servers from Linux (what I recommended a few years ago > when I didn't know different :)) One of the admins (who has some Linux > experience) asked me why it was using swap. I gave the canonical reply. > He asked the question I just posed. I had no good reply :( > The actual reply is the required size of swap is the sum of the size of all process private memory. I don't account for that anywhere, but might just put together a solution. On my workstation, I run with 1.2GB of available swap space, and anybody can afford that, can't they? (BTW, I seldom use more than 30-40MB, but with the price of disk, who cares?) The needed amount of physical memory is best judged by paging activity, but again, the system doesn't tell you directly. -- John | Never try to teach a pig to sing, dyson@freebsd.org | it just makes you look stupid, jdyson@nc.com | and it irritates the pig. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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