### post-fix: cross-slice read attempt:
open /dev/vn0s1a: No such file or directory
### post-fix: wraparound read attempt:
open /dev/vn0s1b: No such file or directory
### post-fix: universal-window write attempt:
open /dev/vn0s1c: No such file or directory
### post-fix: raw label magic intact at abs LBA 2049:
00000000  59 4c 46 c4 e3 45 74 81  00 02 00 00 10 00 00 00  |YLF..Et.........|
### post-fix: control EROFS still enforced (whole-slice write sec 1):
write(/dev/vn0s1, sec=1) = 512 errno=0 (ok)
### guest stable:  7:37AM  up 1 min, 0 users, load averages: 0.11, 0.05, 0.02