Date: Mon, 1 Oct 2007 14:34:57 +0200 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: Robert Milkowski <rmilkowski@task.gda.pl> Cc: freebsd-fs@freebsd.org, Neil Perrin <Neil.Perrin@Sun.COM>, Roch - PAE <Roch.Bourbonnais@Sun.COM>, zfs-discuss@opensolaris.org Subject: Re: [zfs-discuss] ZFS (and quota) Message-ID: <20071001123457.GE35764@garage.freebsd.pl> In-Reply-To: <14950433.20071001125705@task.gda.pl> References: <BE54DA53-0353-4EB3-B232-6A7193522582@stromnet.se> <20070920115621.GF4517@garage.freebsd.pl> <8B5FB4B1-2398-491C-95F4-E79361606916@stromnet.se> <20070921142540.GB5690@garage.freebsd.pl> <18167.56892.707010.947405@gargle.gargle.HOWL> <46FC316A.8010004@Sun.COM> <14950433.20071001125705@task.gda.pl>
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--dFWYt1i2NyOo1oI9 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Oct 01, 2007 at 12:57:05PM +0100, Robert Milkowski wrote: > Hello Neil, >=20 > Thursday, September 27, 2007, 11:40:42 PM, you wrote: >=20 >=20 > NP> Roch - PAE wrote: > >> Pawel Jakub Dawidek writes: > >> > I'm CCing zfs-discuss@opensolaris.org, as this doesn't look like > >> > FreeBSD-specific problem. > >> >=20 > >> > It looks there is a problem with block allocation(?) when we are ne= ar > >> > quota limit. tank/foo dataset has quota set to 10m: > >> >=20 > >> > Without quota: > >> >=20 > >> > FreeBSD: > >> > # dd if=3D/dev/zero of=3D/tank/test bs=3D512 count=3D20480 > >> > time: 0.7s > >> >=20 > >> > Solaris: > >> > # dd if=3D/dev/zero of=3D/tank/test bs=3D512 count=3D20480 > >> > time: 4.5s > >> >=20 > >> > With quota: > >> >=20 > >> > FreeBSD: > >> > # dd if=3D/dev/zero of=3D/tank/foo/test bs=3D512 count=3D20480 > >> > dd: /tank/foo/test: Disc quota exceeded > >> > time: 306.5s > >> >=20 > >> > Solaris: > >> > # dd if=3D/dev/zero of=3D/tank/foo/test bs=3D512 count=3D20480 > >> > write: Disc quota exceeded > >> > time: 602.7s > >> >=20 > >> > CPU is almost entirely idle, but disk activity seems to be high. > >> >=20 > >>=20 > >>=20 > >> Yes, as we are near quota limit, each transaction group > >> will accept a small amount as to not overshoot the limit. > >>=20 > >> I don't know if we have the optimal strategy yet. > >>=20 > >> -r >=20 > NP> Aside from the quota perf issue, has any analysis been done as to > NP> why FreeBSD is over 6X faster than Solaris without quotas? > NP> Do other perf tests show a similar disparity? > NP> Is there a difference in dd itself? > NP> I assume that it was identical hardware and pool config. (I don't see this e-mail in my ZFS inbox, that's why I'm replaying to Robert's e-mail.) Just to clarify. This was entirely different hardware. My e-mail was __only__ about quota performance in ZFS. Please, do not try to use those results for any other purpose. --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --dFWYt1i2NyOo1oI9 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFHAOlxForvXbEpPzQRAoIIAKCp+7TKzdo00Q5SkDg0DrQFe0kn8QCg3DlO 5S3v2IR2pS9pn4+cckSD3WQ= =pxmb -----END PGP SIGNATURE----- --dFWYt1i2NyOo1oI9--
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