William Fretts-Saxton <william.fretts.saxton <at> sun.com> writes: > > I disabled file prefetch and there was no effect. > > Here are some performance numbers. Note that, when the application server > used a ZFS file system to save its data, the transaction took TWICE as long. > For some reason, though, iostat is showing 5x as much disk > writing (to the physical disks) on the ZFS partition. Can anyone see a > problem here?
Possible explanation: the Glassfish applications are using synchronous writes, causing the ZIL (ZFS Intent Log) to be intensively used, which leads to a lot of extra I/O. Try to disable it: http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide#Disabling_the_ZIL_.28Don.27t.29 Since disabling it is not recommended, if you find out it is the cause of your perf problems, you should instead try to use a SLOG (separate intent log, see above link). Unfortunately your OS version (Solaris 10 8/07) doesn't support SLOGs, they have only been added to OpenSolaris build snv_68: http://blogs.sun.com/perrin/entry/slog_blog_or_blogging_on -marc _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
