growfs failure

[javocado]

While trying to growfs a filesystem, I receive the following error:

growfs: rdfs: read error: 5812093147771869908: Input/output error

Here were the steps taken leading up to this point:

(original file is 300 GB, growing to 500 GB)

(the filesystem is clean with fsck_ufs /dev/md1)

geli detach /dev/md1.eli

mdconfig -d -u 1

truncate -s +200G geli.img

mdconfig -f geli.img -u 1

geli resize -s 300G /dev/md1

geli attach /dev/md1

growfs /dev/md1.eli

new file systemsize is: 262143999 frags
Warning: 326780 sector(s) cannot be allocated.
growfs: 511840.4MB (1048249216 sectors) block size 16384, fragment size 2048
        using 2786 cylinder groups of 183.72MB, 11758 blks, 23552 inodes.
super-block backups (for fsck -b #) at:
 629476448, 629852704, 630228960, 630605216, 630981472, 631357728,
631733984, 632110240,
....
growfs: rdfs: read error: 5812093147771869908: Input/output error