Date: Sun, 10 Oct 1999 01:34:13 +0400
From: Dmitrij Tejblum <tejblum@arc.hq.cti.ru>
To: "David Schwartz" <davids@webmaster.com>
Cc: obrien@FreeBSD.ORG, freebsd-current@FreeBSD.ORG
Subject: Re: {a}sync updates (was Re: make install trick)
Message-ID: <199910092134.BAA04136@tejblum.pp.ru>
In-Reply-To: Your message of "Fri, 08 Oct 1999 10:20:03 PDT." <000d01bf11b1$5bfca1f0$021d85d1@youwant.to>
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"David Schwartz" wrote: > We're talking about the special case of small root partitions, such that > softupdates inability to make empty space available quickly can make the > difference between a major operation's success or failure. > > This is almost impossible on a 1.8Gb root partition. [sorry, cannot resist...] <real-life story> Once upon a time, a month or so ago, there were ~30G of free space on our 130G filesystem (with softupdates). An important application that was going to create a ~35G file was running. It already written out 1G or so. My colleague called me and sayed: "I removed a 10G of files TWO HOURS ago and the space didn't free up yet!!! The free space isn't going to appear!!! What do we do now???" Well, after I stopped the application with kill -STOP, and temporary killed off another I/O consuming program, the free space started to appear and after several minutes there were >40G of free space. </real-life story> I think that the problem in this particular case was inability of the syncer to run as fast as it supposed to. It is assummed that syncer fsync 1/30 of all files and process the softupdates worklist every second. If there are several I/O bound processes running, the syncer will not have enough I/O bandwidth to do this job in the required speed. Perhaps running several syncer processes could help. (OTOH, the machine in question is running a quite old version of FreeBSD-CURRENT, it is possible things are already better. I don't see serious changes in softupdates code from that moment, tough. It is also possible that the machine is mistuned in some way, but I don't know how :-() Dima To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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