On Jun 29, 2009 13:41 +0200, Jens Axboe wrote: > ... externally it just makes the API worse since tools then have to know > which device type they are talking to. > > So I still see absolutely zero point in making such a change, quite the > opposite. Exactly correct. Changing these tunables just for the sake of giving them a slightly different name is madness. Making all block devices appear more uniform to userspace (even if they don't strictly need all of the semantics) is very sensible. The whole point of the kernel is to abstract away the underlying details so that userspace doesn't need to understand it all again. In order to get good throughput on RAID arrays we need to tune the queue/max_* values to ensure the IO requests don't get split. It would be great if the MD queue/max_* values would pass these tunings down to the underlying disk devices as well. As it stands now, we have to follow the /sys/block/*/slaves tree to set all of these ourselves, and before "slaves/" was introduced it was nigh impossible to automatically tune these values. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
