Date: Thu, 8 Jan 2009 11:19:59 +0200 From: Nikolay Denev <ndenev@gmail.com> To: fbsd@dannysplace.net Cc: freebsd-fs@freebsd.org, Jeremy Chadwick <koitsu@FreeBSD.org>, freebsd-hardware@freebsd.org Subject: Re: Areca vs. ZFS performance testing. Message-ID: <BCA7594A-27EF-4209-9752-E749BACC87BE@gmail.com> In-Reply-To: <496549D9.7010003@dannysplace.net> References: <20081031033208.GA21220@icarus.home.lan> <490A849C.7030009@dannysplace.net> <20081031043412.GA22289@icarus.home.lan> <490A8FAD.8060009@dannysplace.net> <491BBF38.9010908@dannysplace.net> <491C5AA7.1030004@samsco.org> <491C9535.3030504@dannysplace.net> <CEDCDD3E-B908-44BF-9D00-7B73B3C15878@anduin.net> <4920E1DD.7000101@dannysplace.net> <F55CD13C-8117-4D34-9C35-618D28F9F2DE@spry.com> <20081117070818.GA22231@icarus.home.lan> <496549D9.7010003@dannysplace.net>
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 8 Jan, 2009, at 02:33 , Danny Carroll wrote: > I'd like to post some results of what I have found with my tests. > I did a few different types of tests. Basically a set of 5-disk tests > and a set of 12-disk tests. > > I did this because I only had 5 ports available on my onboard =20 > controller > and I wanted to see how the areca compared to that. I also wanted to > see comparisons between JBOD, Passthru and hardware raid5. > > I have not tested raid6 or raidz2. > > You can see the results here: > http://www.dannysplace.net/quickweb/filesystem%20tests.htm > > An explanation of each of the tests: > ICH9_ZFS 5 disk zfs raidz test with onboard SATA > ports. > ARECAJBOD_ZFS 5 disk zfs raidz test with Areca SATA > ports configured in JBOD mode. > ARECAJBOD_ZFS_NoWriteCache 5 disk zfs raidz test with Areca SATA = =09 > ports configured in JBOD mode and with > disk caches disabled. > ARECARAID 5 disk zfs single-disk test with Areca > raid5 array. > ARECAPASSTHRU 5 disk zfs raidz test with Areca SATA = ports > configured in Passthru mode. This > means that the onboard areca cache is > active. > ARECARAID-UFS2 5 disk ufs2 single-disk test = with Areca > raid5 array. > ARECARAID-BIG 12 disk zfs single-disk test with Areca > raid5 array. > ARECAPASSTHRU_12 12 disk zfs raidz test with Areca SATA = ports > configured in Passthru mode. This > means that the onboard areca cache is > active. > > > I'll probably be opting for the ARECAPASSTHRU_12 configuration. =20 > Mainly > because I do not need amazing read speeds (network port would be > saturated anyway) and I think that the raidz implementation would be > more fault tolerant. By that I mean if you have a disk read error > during a rebuild then as I understand it, raidz will write off that > block (and hopefully tell me about dead files) but continue with the > rest of the rebuild. > > This is something I'd love to test for real, just to see what happens. > But I am not sure how I could do that. Perhaps removing one drive, =20= > then > a few random writes to a remaining disk (or two) and seeing how it =20 > goes > with a rebuild. > > Something else worth mentioning. When I converted from JBOD to > passthrough, I was able to re-import the disks without any problems. > This must mean that the areca passthrough option does not alter the =20= > disk > much, perhaps not at all. > > After a 21 hour rebuild I have to say I am not that keen to do more of > these tests, but if there is something someone wants to see, then I'll > definitely consider it. > > One thing I am at a loss to understand is why turning off the disk > caches when testing the JBOD performance produced almost identical =20 > (very > slightly better) results. Perhaps it was a case of the ZFS internal > cache making the disks cache redundant? Comparing to the ARECA > passthrough (where the areca cache is used) shows again, similar =20 > results. > > -D > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" There is a big difference betweeen hardware and ZFS raidz with 12 disk =20= on the get_block test, maybe it would be interesting to rerun this test with zfs prefetch =20 disabled? - -- Regards, Nikolay Denev -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (Darwin) iEYEARECAAYFAkllxT8ACgkQHNAJ/fLbfrnHnwCeJ8nSjBY6fc0Lvu2+fSN5E4HI zb0Ani2ZFLdxYCWYBuCnoo+D244O2lg5 =3DEKgi -----END PGP SIGNATURE-----
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