Date: Sat, 1 Jan 2011 11:00:19 +1100 From: Peter Jeremy <peterjeremy@acm.org> To: Adam Stylinski <kungfujesus06@gmail.com> Cc: freebsd-stable@freebsd.org Subject: Re: slow ZFS on FreeBSD 8.1 Message-ID: <20110101000019.GC48579@server.vk2pj.dyndns.org> In-Reply-To: <20101230073130.GA55431@zephyr.adamsnet> References: <20101230073130.GA55431@zephyr.adamsnet>
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--eAbsdosE1cNLO4uF Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2010-Dec-30 02:31:30 -0500, Adam Stylinski <kungfujesus06@gmail.com> wro= te: >I can tell you what the problem is right now, actually. ZFS performs >very poorly on low performance CPUs (i.e. your Atom N330). I would disagree. In this case, the op's most serious problem is a bug in sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c:arc_memory_throttle() which is leading to ARC starvation. The direct effect of this is very poor ZFS I/O performance. It can be identified by very high "inactive" and possibly "cache" memory (as reported by 'systat -v' or top) as well as very high kstat.zfs.misc.arcstats.memory_throttle_count This bug was fixed in r210427 on -current, r211599 on 8.x and r211623 on 7.x. > Try the >same system with a different CPU and you'll get a different result. Not until the above bug is fixed. That said, ZFS is far more CPU intensive than UFS and a more powerful CPU may help - especially if you want gzip compression and/or sha256 checksumming. --=20 Peter Jeremy --eAbsdosE1cNLO4uF Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.15 (FreeBSD) iEYEARECAAYFAk0ebpMACgkQ/opHv/APuIevnACfXrm4QSBnEJADZS2s9QrCFzgd gb0AoIKFyJbGPgepu22cevpIKvz3BG16 =mgI4 -----END PGP SIGNATURE----- --eAbsdosE1cNLO4uF--
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