> Read the ATA and SCSI specifications. Or ask on either mailing list. > In short, the drive presents its LBA addressing based on 512B sectors. > The kernel can't choose to ignore that--it's stuck with it. Since the > drive is presenting LBA based on 512B sectors, there is no way the > kernel can address LBA based on 4K sectors.
I don't follow: what prevents the kernel from telling the higher-up tools that the drive uses 4KB sectors (or 72KB sectors for that matter)? >> In any case, the issue is probably not really in the kernel but in the >> filesystems and partitioning tools: all that's really needed to use the > The current "problem" with the hybrid drives is that the partitioning > utilities don't automatically align partitions on the underlying 4k > sector boundaries. I'm glad we agree. >> Indeed, and for that reason 4KB physical blocks wouldn't cause >> additional disk space usage. > The space savings with 4KB sectors has nothing to do with file systems > or user data. I was talking about the space usage increase incurred from the use of ≥4KB blocks in the FS, if we assume that the FS uses the underlying HD block size as a lower-limit of its own block size. > This is the ONLY reason these 4KB sector drives were developed: more > actual end user space on the drive. That's a different topic, but an interesting one as well: the gain seems small (e.g. WD has/had two Green 2TB drives, one using 4KB sectors and the other using good'ol 512B sectors, and this using apparently the same underlying head/drive technology, so it seems the gain, if any, was too small to make it to the end user). So why does WD do that? Stefan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/jwvr5cds7ch.fsf-monnier+gmane.linux.debian.u...@gnu.org