Date: Sun, 21 Nov 2004 20:17:37 +0100 From: Hanspeter Roth <hampi@rootshell.be> To: freebsd-questions@freebsd.org Subject: Re: Tracing Disk Activity Message-ID: <20041121191737.GA2270@gicco.homeip.net> In-Reply-To: <41A0B955.8090700@mac.com> References: <20041121093347.GA861@gicco.homeip.net> <41A0B955.8090700@mac.com>
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On Nov 21 at 10:50, Chuck Swiger spoke: > Hanspeter Roth wrote: > >I have set an idle timeout for the hard-disk. But when there is no > >user activity there are frequent disk accesses. > > Yes, this is Unix. Even when there is no user activity, a Unix system > normally is still running a number of daemons such as syslogd which > regularly write to the filesystem. Beyond that, the syncer mechanism tries > to reduce the number of dirty memory buffers every thirty seconds or so. I guess that some daemons are causing disk access. But it must be not only syslogd. Is the syncer causing the disk to spin up even if there is nothing to flush? [...] > Instead you probably will need to mount filesystems read-only and create > RAM disks in a fashion similar to booting off limited-write media like My idea is to transfer those files that are written also when the user is idle to a RAM disk (some from /var/log and dhclient.leases). But I don't want to mount the filesystems read-only. > Compact Flash. Either that, or simply shutdown the system or run zzz to > suspend the system via APM/APCI. This is less convenient and probably doesn't work on my laptop. (I have to check whether the upgrade to 5.3R has changed something in this respect.) -Hanspeter
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