Date: Sat, 21 Jul 2007 08:52:04 +0200 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: Mark Powell <M.S.Powell@salford.ac.uk> Cc: freebsd-fs@freebsd.org Subject: Re: ZfS & GEOM with many odd drive sizes Message-ID: <20070721065204.GA2044@garage.freebsd.pl> In-Reply-To: <20070719181313.G4923@rust.salford.ac.uk> References: <20070719102302.R1534@rust.salford.ac.uk> <20070719135510.GE1194@garage.freebsd.pl> <20070719181313.G4923@rust.salford.ac.uk>
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--LZvS9be/3tNcYl/X Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jul 19, 2007 at 06:19:14PM +0100, Mark Powell wrote: > On Thu, 19 Jul 2007, Pawel Jakub Dawidek wrote: >=20 > >On Thu, Jul 19, 2007 at 11:19:08AM +0100, Mark Powell wrote: > >> What I want to know is, does the new volume have to be the same actual > >>device name or can it be substituted with another? > >> i.e. can I remove, for example, one of the 448GB gconcats e.g. gc1 and > >>replace that with a new 750GB drive e.g. ad6? > >> Eventually so that once all volumes are replaced the zpool could be, = for > >>example, 4x750GB or 2.25TB of usable storage. > >> Many thanks for any advice on these matters which are new to me. > > > >All you described above should work. >=20 > Thanks Pawel. For your response and much so for all your time spent=20 > working on ZFS. >=20 > Should I expect much greater CPU usage with ZFS? > I previously had a geom raid5 array which barely broke a sweat on=20 > benchmarks i.e simple large dd read and writes. With ZFS on the same=20 > hardware I notice 50-60% system CPU usage is usual during such tests.=20 > Before the network was a bottleneck, but now it's the zfs array. I=20 > expected it would have to do a bit more 'thinking', but is such a dramati= c=20 > increase normal? Be sure to turn off debugging, ie. remove WITNESS, INVARIANTS and INVARIANT_SUPPORT options from your kernel configuration. Other than that, ZFS may just be more CPU hungry... --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --LZvS9be/3tNcYl/X Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFGoa0UForvXbEpPzQRAl5oAKCtt0QPpNfWvPh2aBnIP0I/G/qjuwCgjOQ3 Yp1Kg6GDa1+FasS0vrqdW0U= =W6Xz -----END PGP SIGNATURE----- --LZvS9be/3tNcYl/X--
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