This is just a proof of concept set of patches. I'd like some feedback before I spend more time on them. At the Filesystem & Storage Workshop there was lots of discussion about how to communicate I/O alignment, stripe width, etc. to the filesystems so they could lay out things properly. An addition to the up-and-coming version of the SCSI block protocol features an inquiry page that hardware RAIDs can use to indicate preferred I/O sizes for a given LUN. This patch kit implements support for exporting those values in /sys/block/. I have implemented support for it in sd.c using the Block Limits VPD and in MD using chunk size and stripe width. The physical sector offset for the start of the "virtual" block device is also exported. This includes partitions so you can get the actual physical start sector offset for - say - an MD device sitting on a partitioned set of drives. Comments and suggestions are welcome. -- Martin K. Petersen Oracle Linux Engineering -- 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
