Date: Fri, 8 Feb 2008 09:16:52 -0800 (PST) From: "millueradfa@yahoo.com" <millueradfa@yahoo.com> To: "Jason C. Wells" <jcw@highperformance.net>, freebsd-questions@freebsd.org Subject: Re: Some ideas for FreeBSD Message-ID: <229884.2551.qm@web34506.mail.mud.yahoo.com> In-Reply-To: <47AB9DA9.8080006@highperformance.net>
next in thread | previous in thread | raw e-mail | index | archive | help
--- "Jason C. Wells" <jcw@highperformance.net> wrote: > Heiko Wundram (Beenic) wrote: > > Am Donnerstag, 7. Februar 2008 07:32:16 schrieb > Jason C. Wells: > >> Norberto Meijome wrote: > >>> But I agree with Wojciech..do you really want to > use swap files? > >> One could mount an md filesystem and then use > that as swap. That way > >> you wouldn't need to use any disc space. As a > plus, the performance > >> would be way better than disc. > > > > Ahem, sorry, that's just plain stupid. Either the > md system is backed up by > > RAM (in which case you don't need the swap anyway; > why'd you want to access > > RAM by putting it in a swap on an md in RAM?), or > it's backed up by swap, in > > which case you have a chicken and egg problem. > > Mmm, yes. That is quite a pickle. But a chicken or > an egg would still > be inferior to an md backed swap. :) > > Regards, > Jason > > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to > "freebsd-questions-unsubscribe@freebsd.org" > Actually, you can have file backed swap files. I have done it. However, with more than one swap file, or a swap file and a swap partition on the same disk, there ends up being quite a bit of thrashing. This is due apparently to some interaction between having two swaps on the same disk but that is jut a guess, i dont know what the cause is. The idea behind having swap files is that swap space can more easily be expanded and added on the fly. If your initial swap partition was not big enough it is more easy to more swap in another file. As well, a swap file that can grow and shrink, also would allow you to avoid having a lot of disk space consumed by unused swap, so he disk space is allocated when needed, or allow more space to easily be added if you find out you do not have enough. With applications crashing because of swap partition running out, this would be an important feature, since more swap space can be allocated in a file which is easier to do than a partition. Swap is still important on systems with small amounts of RAM, FreeBSD should be able to run on some older hardware too and should not be like Windows where you have to have 2 GHZ 2 GB of ram to run it. dynamic swap space makes it more versatile which is a good thing ____________________________________________________________________________________ Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?229884.2551.qm>