I copied all files from /mnt/wd1l to /mnt/wd2l wd2l is slightly larger than wd1l; yet wd2l is full!
$ df -h /mnt/wd1l /mnt/wd2l Filesystem Size Used Avail Capacity Mounted on /dev/wd1l 1020G 952G 16.5G 98% /mnt/wd1l /dev/wd2l 1020G 969G -508M 100% /mnt/wd2l Output from disklabel is almost identical: type: SCSI disk: SCSI disk label: WDC WD2000FYYZ-0 flags: bytes/sector: 512 sectors/track: 63 tracks/cylinder: 255 sectors/cylinder: 16065 cylinders: 243201 total sectors: 3907029168 rpm: 0 interleave: 1 trackskew: 0 cylinderskew: 0 headswitch: 0 # microseconds track-to-track seek: 3907029168 # microseconds drivedata: 0 Difference between wd1 and wd2: wd1: interleave: 0 wd2: interleave: 1 Partition details (A added 'wd1/wd2' to beginning of line: # size offset fstype [fsize bsize cpg] wd1l: 2147472640 525486208 4.2BSD 8192 65536 1 wd2l: 2147483647 63 4.2BSD 8192 65536 1 Why is wd2l full?