Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!snorkelwacker!paperboy!meissner From: meissner@osf.org (Michael Meissner) Newsgroups: comp.unix.wizards Subject: Re: Buffer flushing Message-ID: Date: 7 May 90 15:15:25 GMT References: <911@sixhub.UUCP> Sender: news@OSF.ORG Followup-To: comp.unix.wizards Organization: Open Software Foundation Lines: 25 In-reply-to: davidsen@sixhub.UUCP's message of 4 May 90 03:07:57 GMT In article <911@sixhub.UUCP> davidsen@sixhub.UUCP (Wm E. Davidsen Jr) writes: | Most flavors of SysV and some BSD systems have a process which does a | sync from time to time, such as "update." When the kernel is configured | to have a large number of buffers the result is a slowdown in | performance for disk intensive tasks. | | Many versions provide a tuning parameter which allows this to happen | more or less often, but it still happens all at once. What I would like | is a way to force or at least encourage the system to write dirty | buffers out as a idle task, so that if the CPU is available and there | are dirty buffers they are queued, but only at some faitly slow rate, | perhaps 3-5% of the buffers per second. The only problem with doing this only as an idle task, is that you risk losing lots of data if you have a crash when the system hasn't been idle for awhile (remember murphy after all). You could of course have a general sync, say every 5 minutes or so in addition to doing it on idle cycles. -- Michael Meissner email: meissner@osf.org phone: 617-621-8861 Open Software Foundation, 11 Cambridge Center, Cambridge, MA Catproof is an oxymoron, Childproof is nearly so