Guennadi Liakhovetski wrote: > On Thu, 5 Oct 2006, Jeff Garzik wrote: > >> Guennadi Liakhovetski wrote: >>> On Wed, 4 Oct 2006, James Bottomley wrote: >>> >>>> This is (hopefully) my final batch of updates before we go -rc1. It's >>>> mainly code cleanups, some driver updates and the new qla4xxx iScsi >>>> driver. >>> James, is there a reason why you didn't include this one: >>> >>> http://marc.theaimsgroup.com/?l=linux-scsi&m=115974328128341&w=2 >>> >>> Do you think it can cause problems? >> It would be nice to get it tested, based on your "don't know if it works >> though" comment... > > Sure, it WOULD be nice, but I don't know how. The "don't know" refers to > the case 16MB block size, my tape supports only 16MB - 1 byte (according > to st report). Is there a way to test various block sizes with CDs / > hard-disks / ZIP / scanners? > Would something with sg_dd work? Interesting challenge. In lk 2.6.19-rc1 with /dev/sda and /dev/sg0 the same SCSI disk I can get close: [root@sas parameters]# cd /sys/block/sda/queue/ [root@sas queue]# echo 32767 > max_sectors_kb [root@sas queue]# cd /sys/module/sg/parameters/ [root@sas parameters]# echo 131072 > scatter_elem_sz [root@sas parameters]# sg_dd if=/dev/sg0 of=/dev/null bs=512 bpt=32640 count=32k verbose=3 >> Input file type: SCSI generic (sg) device open input(sg_io), flags=0x800 inquiry cdb: 12 00 00 00 24 00 /dev/sg0: SEAGATE ST336754SS 0003 [pdt=0] >> Output file type: null device read cdb: 28 00 00 00 00 00 00 7f 80 00 duration=180 ms read cdb: 28 00 00 00 7f 80 00 00 80 00 duration=4 ms 32768+0 records in 32768+0 records out So I got within 128 (512 byte) sectors of a 16 MB transfer on a single command. Hmm. This is with a adaptec 48300 HBA with the aic94xx driver (take your pick which one). Looks like > it must be only sector size. Can I low-level format a disk with 16M > sector?:-) No usually. Some SCSI disk can be formatted up to 528 byte sectors but that is a long way short. > Another possibility is to limit the block size at 8MB - I can test that. The sg driver gets around that in lk 2.6.19-rc1 Doug Gilbert - 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
