scsi disk sector size question
There's gotta be a better place to ask this, but...
Greetings,
Is it possible to change scsi drive sector size? Scsiinfo says no, which is inconvenient if you're making images of ancient drives (ST4766N) and find that some have 512 byte and others 1024 byte sectors.
Why on earth would a manufacturer [drives are really CDC] do this?
-Mike
Quoted 6 lines · Mike Galbraith
There's gotta be a better place to ask this, but...
Greetings,
Is it possible to change scsi drive sector size?
The hardware sector size? It depends on the drive. Some may let you do it, this usually requires a low-level format, possibly using litte-documented vendor specific tricks.
Quoted 3 lines
Scsiinfo says no, which is
inconvenient if you're making images of ancient drives (ST4766N) and find that some have 512 byte and others 1024 byte sectors.
Having two scripts, one for each case is too bad?
Quoted 1 line
Why on earth would a manufacturer [drives are really CDC] do this?
You should really ask the manufacturer. One reason may be to squeeze more data onto the disk. Each sector has some overhead on the magnetic surface, such as crc data and sector gaps. And the sector number is written too so the disk firmware knows where the head is - this is why you need a low-level format when changing. You need to write new sector numbers for the different-sized sectors.
The overhead means you get more data on the disk by using larger sectors. Fewer sectors in total means less overhead when per-sector overhead adds upp.
Helge Hafting