The disk nameplate data shows 6218 cylinders, 16 heads, and 63 sectors. The installed Maxtor hard disk is a model 83201A6.

That leaves adjusting Cylinders, Heads, and Sectors. While there are several settings, two do not apply to almost all PATA/IDE hard disks - WPcom and LZone. The only possible option with the 486 BIOS is a “type 47” for “user defined.” No so straightforward with the 486 system. This is straightforward to change on the K6-III+ system. The limitation can be bypassed if the BIOS supports logical block addressing (LBA). Similarly, running scandisk or the Norton Disk Doctor will halt with bad block errors at that location in the partition. The caveat is MS-DOS will seem satisfied installing to a 2 GB partition - until trying to access the partition beyond that limit. Commonly on vintage systems the BIOS was limited to 504 MiB (528 MB) partitions. The FAT-16 file system supported partitions up to 2 GB, but often the BIOS limited that support. With a physical machine using a 2 GB partition is not straightforward. This is a red herring because the virtual backend is designed to be as compatible and flexible as possible. In a virtual machine I had no problems installing MS-DOS into a 2 GB partition. Traveling this road required me to remember esoteric information about how hard disk technology evolved. This is not critical and mostly an intellectual challenge. I returned to my previous effort to use MS-DOS with a 2 GB C: partition.

Probably not surprising, the modern fsck.msdos seems to be more strict or robust about file system integrity. Odd the native scandisk found no errors but in perspective that tool is 30 years old. To be safe I again tested the disk with scandisk. This time after creating the backup image I could mount through the loop device. I returned the hard disk to the test box and let fsck.msdos correct the alleged file system errors. I restored the hard disk into the 486 and ran scandisk. I ran fsck.msdos and some files allegedly had not been deleted properly. Apparently the mount command believed the file system dirty bit was set. Oddly, I could not use the loop device to access the image backup. After configuring the 486 system I created a dd image snapshot backup.

Maxtor disk doctor