Hello Matthew, Thursday, August 10, 2006, 4:50:31 PM, you wrote:
MA> On Thu, Aug 10, 2006 at 11:48:09AM +0200, Robert Milkowski wrote: >> MA> This test fundamentally requires waiting for lots of syncronous writes. >> MA> Assuming no other activity on the system, the performance of syncronous >> MA> writes does not scale with the number of drives, it scales with the >> MA> drive's write latency. >> >> MA> If you were to alter the test to not require everything to be done >> MA> synchronously, then you would see much different behavior. >> >> Does it mean that instead of creating one pool if I create two pools >> with the same numbers of disks in summary, and run two tests at the >> same time each on its own pool I should observe better scaling than >> with one pool with all disks? MA> Yes, but a better solution would be to use one pool with multiple MA> filesystems. MA> The intent log is per filesystem, so if you can break up your workload MA> into sub-loads that don't depend on the others being on disk MA> synchronously, then you can put each sub-load on a different filesystem, MA> and it will scale approximately with the number of filesystems. That is great news as that is exactly what I'm doing right now (many fs'es in a single pool) and going to do. Thank you for info. btw: wouldn't it be possible to write block only once (for synchronous IO) and than just point to that block instead of copying it again? IIRC raiserfs folks are trying to implement something like this. -- Best regards, Robert mailto:[EMAIL PROTECTED] http://milek.blogspot.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
