The script /etc/periodic/daily/223.backup-zfs should save informations about zpool and zfs layout and some useful properties. These informations should be useful for recreating the pool layout after some disaster (machine parseable?). I am the author of the original version from the PR 86388 and this was my intention. There should not be any statistical information (compress ratio, space usage etc.) These commands were used for this in the original 223.backup-zfs zpool list -vp zfs list -p -H -o name,mountpoint zfs get -H -p -t filesystem,volume all | grep -E -v "available|compressratio|logicalreferenced|logicalused|refcompressratio|referenced|used|usedbychildren|usedbydataset|written" zpool get -H -p all | grep -E -v "capacity|dedupratio|free|allocated|fragmentation" They were changed in committed version to simple zpool list zfs list zfs get zpool get But this breaks some things. Current and previous backup files are compared and differencies are being e-mailed. This committed version will see differences in things like compress ratio, space usage and other things which should not be included in the backed up informations. Then this unuseful informations are being sent to the user just because there is difference in disk space useage Backup of ZFS information for all imported pools 33,34c33,34 < sys/usr 10.0M 12.3G 88K none < sys/usr/home 8.88M 12.3G 1.48M /usr/home --- > sys/usr 10.1M 12.3G 88K none > sys/usr/home 8.89M 12.3G 1.48M /usr/home 42c42 < sys/var/tmp 3.38M 12.3G 148K /var/tmp --- > sys/var/tmp 3.38M 12.3G 140K /var/tmp 84c84 < tank0/vol0/web 265M 9.80T 9.54M /vol0/web --- > tank0/vol0/web 265M 9.80T 9.47M /vol0/web Also I don't see dumping properties for snapshots much useful but it can be painfully slow on systems with a lot of snapshots, that's why my original version had zfs get -H -p -t filesystem,volume all. I see this can be changed in /etc/periodic.conf with daily_backup_zfs_get_flags but I think there should be more sane defaults. I am using the original version from 2017 but now, after upgrading FreeBSD to version with 223.backup-zfs shipped in the base I am seeing long list of changes in each daily e-mail. I really would like to talk to somebody who is in charge for periodic scripts and find a way to make it better for all users. I can provide patches if we agree on what and how should be done.