Last week I setup a new ESXi VM template to move from UFS to ZFS and upgrade to 26.1.
I ran several ZFS unmap tests inflating thin VMDK with large ISO and deleting.
zpool set autotrim=on zroot
System didn't appear to auto trim / unmap within ~30 min.
But running - zpool trim zroot - manual trim worked. VMDK shrunk to very close to exact used space So was happy and proceeded to swap over to new ZFS VM template.
Only been weekend since deployed and now reviewing today VMDK is 47GB yet Opnsense reports only 5GB used?
I've since ran manual trim again but it only shrunk VMDK ~1GB. There is no way this much data has ever been written other than some internal ZFS function.
Is ZFS scrub or compression screwing with thin provisioning unmap / zero space?
I'm at a loss what FreeBSD + ZFS + VMFS thin disk is doing - Any suggestions appreciated.
Thin disk is 80GB
# df -h
Filesystem Size Used Avail Capacity Mounted on
zroot/ROOT/default 69G 5.0G 64G 7% /
devfs 1.0K 0B 1.0K 0% /dev
/dev/gpt/efiboot0 260M 1.3M 259M 1% /boot/efi
zroot/var/mail 64G 160K 64G 0% /var/mail
zroot/var/log 64G 31M 64G 0% /var/log
zroot/usr/src 64G 96K 64G 0% /usr/src
zroot/tmp 64G 206M 64G 0% /tmp
zroot 64G 96K 64G 0% /zroot
zroot/usr/ports 64G 96K 64G 0% /usr/ports
zroot/var/audit 64G 96K 64G 0% /var/audit
zroot/home 64G 96K 64G 0% /home
zroot/var/crash 64G 96K 64G 0% /var/crash
zroot/var/tmp 64G 388K 64G 0% /var/tmp
devfs 1.0K 0B 1.0K 0% /var/unbound/dev
/usr/local/lib/python3.13 69G 5.0G 64G 7% /var/unbound/usr/local/lib/python3.13
/lib 69G 5.0G 64G 7% /var/unbound/lib
/dev/md43 484M 48K 445M 0% /usr/local/zenarmor/output/active/temp
fdescfs 1.0K 0B 1.0K 0% /dev/fd
procfs 8.0K 0B 8.0K 0% /proc
tmpfs 100M 24K 100M 0% /usr/local/zenarmor/run/tracefs
# zpool status
pool: zroot
state: ONLINE
config:
NAME STATE READ WRITE CKSUM
zroot ONLINE 0 0 0
da0p4 ONLINE 0 0 0
errors: No known data errors
Edit: Reviewing backup logs the fresh VM template VMDK was 14GB prior to few GB of Zenarmor / NTOPNG data accumulated over weekend.
VMDK has grown around ~29GB beyond what it should be in around 3 days.