Date: Tue, 17 Apr 2007 22:51:23 +0200 From: Max Laier <max@love2party.net> To: freebsd-current@freebsd.org Cc: Thomas Sparrevohn <Thomas.Sparrevohn@btinternet.com> Subject: Re: Some comments on ZFS Message-ID: <200704172251.33377.max@love2party.net> In-Reply-To: <200704172137.11184.Thomas.Sparrevohn@btinternet.com> References: <200704171143.l3HBhDZB008693@peedub.jennejohn.org> <200704172137.11184.Thomas.Sparrevohn@btinternet.com>
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--nextPart27369945.4msuNq8cIk Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Tuesday 17 April 2007 22:37, Thomas Sparrevohn wrote: > On Tuesday 17 April 2007 12:43:13 Gary Jennejohn wrote: > > Robert Watson writes: > > > > Interestingly enough, I see less memory pressure since switching to > > ZFS. But I'm not using RAIDZ. Previously ``make buildworld'' would > > use much more memory, probably for buffer caching. It looks like ZFS > > doesn't use nearly as much buffer cache as UFS (which may not be a > > good thing). > > On this system 4GB system - 2,3GB available - ZFS stops around > 1,3GB Free whereas UFS continues until app. 700MB mark on a > buildworld > > But the price seems to be much more disk activity - Given that > the difference - after disabling Witness - was > > UFS 10m32.10s real 27m1.32s user 7m49.01s sys =20 > (Systat 700MB Free) ZFS 17m43.66s real 27m30.70s user =20 > 17m28.47s sys (Systat 1,3GB Free) > > It make me think that ZFS is trading memory for performance - my guess > is - that given the same memory usage ZFS would be unbeatable - I must > say that Pawel has done a great job porting ZFS I have reverted the 3/4 -> 1/2 arc size limit locally, which gives better=20 results in my test: playing hd video off the same disk while doing a=20 (single threaded) buildworld from the same zpool (single disk, no mirror,=20 no raidz). With the 1/2 limit, I get frequent hick-ups in the playback -=20 while with 3/4 things run (almost) smoothly. =2D-=20 /"\ Best regards, | mlaier@freebsd.org \ / Max Laier | ICQ #67774661 X http://pf4freebsd.love2party.net/ | mlaier@EFnet / \ ASCII Ribbon Campaign | Against HTML Mail and News --nextPart27369945.4msuNq8cIk Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (FreeBSD) iD8DBQBGJTNVXyyEoT62BG0RAlIlAJ0SNN5l5aVD0Jgr73ueujocU98ixQCfab+P 5WztqX9y9yN68vHOZDk7wTY= =K0So -----END PGP SIGNATURE----- --nextPart27369945.4msuNq8cIk--
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