The image file sizes on the host OS file system don't match what RaSCSI reports as the size in the Product string.

F.e.

ls -alh
-rw-r--r-- 1 root root 100M Sep 22 11:12 100b.hds

ls -al
-rw-r--r-- 1 root root 104857600 Sep 22 11:12 100b.hds

rasctl -i 6 -c s
6:0 SCHD RaSCSI:SCSI HD 104 MB:2209 512 bytes per sector 104857600 bytes capacity /home/dmark/images/100b.hds

So effectively, the host OS considers it a 100M file, while RaSCSI calculates it as 104MB. I believe this is the host OS actually calculating MiB (power of 2) while RaSCSI uses MB here (power of 10)