Bob Friesenhahn wrote: > My application processes thousands of files sequentially, reading > input files, and outputting new files. I am using Solaris 10U4. > While running the application in a verbose mode, I see that it runs > very fast but pauses about every 7 seconds for a second or two.
When you experience the pause at the application level, do you see an increase in writes to disk? This might the regular syncing of the transaction group to disk. This is normal behavior. The "amount" of pause is determined by how much data needs to be synced. You could of course decrease it by reducing the time between syncs (either by reducing the ARC and/or decreasing txg_time), however, I am not sure it will translate to better performance for you. hth, -neel This > is while reading 50MB/second and writing 73MB/second (ARC cache miss > rate of 87%). The pause does not occur if the application spends more > time doing real work. However, it would be nice if the pause went > away. > > I have tried turning down the ARC size (from 14GB to 10GB) but the > behavior did not noticeably improve. The storage device is trained to > ignore cache flush requests. According to the Evil Tuning Guide, the > pause I am seeing is due to a cache flush after the uberblock updates. > > It does not seem like a wise choice to disable ZFS cache flushing > entirely. Is there a better way other than adding a small delay into > my application? > > Bob > ====================================== > Bob Friesenhahn > [EMAIL PROTECTED], http://www.simplesystems.org/users/bfriesen/ > GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
