On https://www.freebsd.org/doc/handbook/zfs-zfs.html under heading 19.4.7.2. Sending Encrypted Backups over SSH the text says the following.

"To mount the pool, the unprivileged user must own the directory, and regular users must be allowed to mount file systems. On the receiving system:

# sysctl vfs.usermount=1
vfs.usermount: 0 -> 1
# sysrc -f /etc/sysctl.conf vfs.usermount=1
# zfs create recvpool/backup
# zfs allow -u someuser create,mount,receive recvpool/backup
# chown someuser /recvpool/backup"

When I type the following as using sudo on my 12.1-RELEASE-p2 system I get an error.

[mike@nas ~]$ sudo sysrc -f /etc/sysctl.conf vfs.usermount=1
sysrc: vfs.usermount: name contains characters not allowed in shell

When I change to the root user I get the same error.

[mike@nas ~]$ sudo -i
root@nas:~ # sysrc -f /etc/sysctl.conf vfs.usermount=1
sysrc: vfs.usermount: name contains characters not allowed in shell


It seems like the valid characters variable in /usr/share/bsdconfig/sysrc.subr  is incorrect.

VALID_VARNAME_CHARS="0-9ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_"

Should it include a period?

Also, I believe the documentation should clarify when a user needs to run as root versus when to run as a non-root user. At least it seems like every command should be run as root but it is not clear.

I had to manually edit the /etc/sysctl.conf file.