Ungo (a.nony.mous@soum.ynon.a) on 9/22/08 wrote:
---------------------------
>Linus Torvalds (torvalds@linux-foundation.org) on 9/22/08 wrote:
>---------------------------
>>I just don't
>>care too much personally, since nobody uses 512-byte blocks
>>anyway.
>
>Speaking of which...
>
>I seem to recall reading a year or 2 ago that people in the storage industry were
>agitating for a changeover to 4096 byte blocks, for reasons which went beyond just
>the fact that nobody uses 512 byte blocks anymore. (Such as less overhead for ECC
>& sector structures on magnetic storage, and I seem to recall they came up with
>a reason why it would also improve the raw BER seen by the disk's controller.)
>Does anybody know of any progress on this front?


Way back in the mid 90s or so I experimented with the low SCSI commands that let you reformat drives with larger sector sizes, and found that I gained something like 7% going to 1K sectors, and I think it was 13% going to 4K sectors, which was the largest that drive would allow (IIRC it was a 2GB Seagate)

I never had the guts to actually use it that way though, even though back then an extra 13% of hard drive space was not be sneezed at (in today's world of super-cheap 1TB drives, I'm afraid I would sneeze at it...) Although I was able to format a filesystem on that drive under HP-UX and it appeared to work normally, I figured there was going to be something that would break somewhere that would make me regret it, so I formatted it back to 512 byte sectors.

So now they are finally going to do it, just when few people really need that extra space!

Have they resolved all the issues with having more than 2^32 sectors for SCSI? For SATA? This would limit drives to 2TB when using 512 byte sectors. I suspect there are still some problems out there (or too many older versions of OS still in common use that couldn't use drives with more than 2^32 sectors) so we'll see 4K sectors just to push out the day of reckoning a few years.