Reformatting SCSI drive to different sector size

I had some old IBM 1GB 0662 drives that were set to use a 524-byte sector size. PC's usually use 512-byte size. On some of the older ESDI drives this can be changed with a simple jumper on the drives PCB, but these fancy c:93 SCSI drives require you to send special SCSI commands to them. Fortunately Linux has something called the sg_utils, details on how to install it, and the utilities are included in the link.

These are powerful utilities that will allow you to brick a drive so be careful. This should work for any drive that can do this. The -6 or --six options are not needed on more modern drives. Try it without, and if it complains then add it.

First lets look at the format mode page:

root@Darc~# sginfo -f -6 /dev/sdc
Format Device mode page (0x3)
-----------------------------
Tracks per Zone                    5
Alternate sectors per zone         16
Alternate tracks per zone          0
Alternate tracks per lu            0
Sectors per track                  105
Data bytes per physical sector     524
Interleave                         1
Track skew factor                  8
Cylinder skew factor               16
Supports Soft Sectoring            0
Supports Hard Sectoring            1
Removable Medium                   0
Surface                            0

root@Darc:~# sg_format --six --format --size=512 /dev/sdc
    IBMRAID   0662S129337       101B   peripheral_type: disk [0x0]
Mode Sense (block descriptor) data, prior to changes:
  Number of blocks=1998835 [0x1e7ff3]
  Block size=524 [0x20c]

A FORMAT will commence in 10 seconds
    ALL data on /dev/sdc will be DESTROYED
        Press control-C to abort
A FORMAT will commence in 5 seconds
    ALL data on /dev/sdc will be DESTROYED
        Press control-C to abort

Format has started
Format in progress, 5.85% done
Format in progress, 12.10% done
Format in progress, 18.75% done
Format in progress, 25.00% done
Format in progress, 31.64% done
Format in progress, 37.89% done
Format in progress, 44.53% done
Format in progress, 50.78% done
Format in progress, 57.42% done
Format in progress, 63.67% done
Format in progress, 70.31% done
Format in progress, 77.34% done
Format in progress, 84.37% done
Format in progress, 91.79% done
Format in progress, 99.21% done
FORMAT Complete

root@Darc:~# sginfo -f -6 /dev/sdc
Format Device mode page (0x3)
-----------------------------
Tracks per Zone                    5
Alternate sectors per zone         16
Alternate tracks per zone          0
Alternate tracks per lu            0
Sectors per track                  108
Data bytes per physical sector     512
Interleave                         1
Track skew factor                  8
Cylinder skew factor               16
Supports Soft Sectoring            0
Supports Hard Sectoring            1
Removable Medium                   0
Surface                            0

root@Darc:~# cfdisk /dev/sdc   gives FATAL ERROR: Cannot read disk drive

root@Darc:~# cfdisk /dev/sdc   

root@Darc:~# mkfs /dev/sdc1