Date: Wed, 20 Jan 2010 01:03:41 +0100 From: "O. Hartmann" <ohartman@mail.zedat.fu-berlin.de> To: =?UTF-8?B?TW9yZ2FuIFdlc3N0csO2bQ==?= <freebsd-questions@pp.dyndns.biz> Cc: FreeBSD Stable <freebsd-stable@freebsd.org>, freebsd-questions@freebsd.org Subject: Re: immense delayed write to file system (ZFS and UFS2), performance issues Message-ID: <4B56485D.2010303@mail.zedat.fu-berlin.de> In-Reply-To: <4B54C5EE.5070305@pp.dyndns.biz> References: <4B54C100.9080906@mail.zedat.fu-berlin.de> <4B54C5EE.5070305@pp.dyndns.biz>
next in thread | previous in thread | raw e-mail | index | archive | help
On 01/18/10 21:34, =EF=BF=BD wrote: > O. Hartmann wrote: >> I realise a strange behaviour of several FreeBSD 8.0-STABLE/amd64 boxe= s. >> All boxes have the most recent STABLE. One box is a UP system, two >> others SMP boxes, one with a Q6600 4-core, another XEON with 2x 4-core= s >> (Dell Poweredge III). >> >> Symptome: All boxes have ZFS and UFS2 filesystems. Since two weeks or >> so, sometimes the I/O performance drops massively when doing 'svn >> update', 'make world' or even 'make kernel'. It doesn't matter what >> memory and how many cpu the box has, it get stuck for several seconds >> and freezing. On the UP box, this is sometimes for 10 - 20 seconds. >> A very interesting phenomenon is the massively delayed file writing on= >> ZFS filesystems I realise. Editing a file in 'vi' running on one XTerm= >> and having in another Xterminal my shell for compiling this file, it >> takes sometimes up to 20 seconds to get the file updated after it has >> been written. It's like having an old, slow NFS connection with long >> cache delays. >> These massively delayed file transactions are not necessarely under >> heavy load, sometimes they occur in a relaxed situation. They seem to >> occur much more often on the UP box than on the SMP boxes, but this >> strange phenomenon also occur on the Dell Poweredge II, which has 16GB= >> RAM and summa summarum 16 cores. This phenomenon does occur on ZFS- an= d >> UFS2 filesystems as well. It is hardly reproducable. >> >> Is there any known issue? >> >> Ragrds, >> Oliver > > > The disks involved don't happen to be Western Digital Green Power disks= , > do they? The Intelli-Park function in these disks are wrecking havoc > with I/O in Linux-land at least, causing massive stalls and iowait > through the roof during the 25-30 seconds it takes for the heads to > unload after parking. I have two of these disks sitting on my desk now > collecting dust... > /Morgan > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.or= g" The disks in question are indeed WD on one box, but they are all Caviar=20 Black and they performed well months ago with the very same hardware and = an earlier FreeBSD 8 version. The other boxes in questions do have a set of mixed type, Seagate, WD,=20 Samsung (mostly Samsung F1 types). We do not use 'Green' drives, due to=20 every box acts as a server and we found green-disks, even from WD, too sl= ow. Oliver
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4B56485D.2010303>