G'Day Trond, On Thu, 20 Jul 2006, Trond Norbye wrote:
> I have been using iosoop script (see > http://www.opensolaris.org/os/community/dtrace/scripts/) written by > Brendan Gregg to look at the IO operations of my application. When I was > running my test-program on a UFS filesystem I could see both read and > write operations like: The most up to date version would be in the DTraceToolkit, but that shouldn't cause a problem here. > UID PID D BLOCK SIZE COMM PATHNAME > 203803 4436 R 6016592 16384 diskio <none> > 203803 4436 W 3448432 16384 diskio <none> > 203803 4436 R 5510832 16384 diskio <none> > 203803 4436 W 4652608 16384 diskio <none> > > But when I'm running my program on a ZFS file-system, I can only see > the read io transfers: > > UID PID D BLOCK SIZE COMM PATHNAME > 203803 4445 R 2647296 131072 diskio <none> > 203803 4445 R 1351168 131072 diskio <none> > > So how can I get the same information from a ZFS file-system? Firstly, we need to bear in mind that iosnoop matches on disk I/O, not application level I/O. Many writes will be cached in memory and flushed sometime later to disk, asynchronously. That's when iosnoop picks it up. Were you matching on a process name or PID? no worries, Brendan _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
