Please allow me to contribute some to this question, since this relates to the protocol question years ago that I could not give an answer in a few seconds. [and I still cannot do that today -- no need, I insist.]
File I/O and block I/O is very different. While block I/O measurements could be used for accross-platform comparisons (with various block protocols, since they all should carry very little overhead), file I/O heavily depends on the file protocols. Some file protocols are built with other preserved usage such as security and directory services, but carrying extra overhead for those. Hence, when doing file I/O comparisons, you will have to keep in mind that file I/O technologies were not invented for ultimate performance. Block I/O is. Numbers are numbers, but how do you use them makes a huge impact on your conclusions. :-) Best, z ----- Original Message ----- From: "Thomas Garner" <thomas...@gmail.com> To: "Brad" <bst...@aspirinsoftware.com> Cc: <zfs-discuss@opensolaris.org> Sent: Saturday, January 17, 2009 4:04 PM Subject: Re: [zfs-discuss] Aggregate Pool I/O > Are you looking for something like: > > kstat -c disk sd::: > > Someone can correct me if I'm wrong, but I think the documentation for > the above should be at: > > http://src.opensolaris.org/source/xref/zfs-crypto/gate/usr/src/uts/common/avs/ns/sdbc/cache_kstats_readme.txt > > I'm not sure about the file i/o vs disk i/o, but would love to hear > how to measure it. > > Thomas > > On Sat, Jan 17, 2009 at 4:07 AM, Brad <bst...@aspirinsoftware.com> wrote: >> I'd like to track a server's ZFS pool I/O throughput over time. What's a >> good data source to use for this? I like zpool iostat for this, but if I >> poll at two points in time I would get a number since boot (e.g. 1.2M) >> and a current number (e.g. 1.3K). If I use the current number then I've >> lost data between polling intervals. But if I use the number since boot >> it's not precise enough to be useful. >> >> Is there a kstat equivalent to the I/O since boot? Some other good data >> source? >> >> And then is there a similar kstat equivalent to iostat? Would both data >> values then allow me to trend file i/O versus physical disk I/O? >> >> Thanks. >> -- >> This message posted from opensolaris.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 _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
