On Oct 19, 2010, at 7:34 PM, Aleksey Tsalolikhin <atsaloli.tech at gmail.com> wrote: > Still seeing the glitch every 5-20 secs after remounting with "commit=6000". > > > On Tue, Oct 19, 2010 at 4:00 PM, Ross Walker <rswwalker at gmail.com> wrote: >> >> You could also reduce the dirty interval in sysctl so it flushes sooner therefore flushes less data each time. > > OK. It's worth a shot. Any idea what the default value is? I'm not > sure what value to put in here. > I know I want to reduce it but I don't want to break my friend's system either. > > http://www.mjmwired.net/kernel/Documentation/sysctl/vm.txt > > 109 dirty_expire_centisecs > 110 > 111 This tunable is used to define when dirty data is old enough to be eligible > 112 for writeout by the pdflush daemons. It is expressed in 100'ths > of a second. > 113 Data which has been dirty in-memory for longer than this interval will be > 114 written out next time a pdflush daemon wakes up. There are several dirty tunables, try a 'sysctl -a | grep dirty' Try limiting both the amount if dirty memory to hold and the number of seconds to hold it. Defaults are way too liberal and if you are processing a lot of data can both expose you to extreme data loss in a system failure and bottle neck your storage during pdflush. -Ross