Solved /usr ZFS dataset not mounted?

[fmc000]

I just noticed a possible anomaly on my system. This is what is mounted:

[11:02][fmc000@tu45b-freebsd ~] $ df -T|grep zfs|sort
zroot               zfs       262452872        96 262452776     0%    /zroot
zroot/ROOT/default  zfs       273647164  11194388 262452776     4%    /
zroot/gdrive        zfs       209715136 139109212  70605924    66%    /gdrive
zroot/home          zfs       262452872        96 262452776     0%    /home
zroot/home/fmc000   zfs        49195348   3355628  45839720     7%    /home/fmc000
zroot/tmp           zfs         5144492     22000   5122492     0%    /tmp
zroot/usr/ports     zfs        46861036   3269964  43591072     7%    /usr/ports
zroot/usr/src       zfs        18231572   1220612  17010960     7%    /usr/src
zroot/var/audit     zfs          102400        96    102304     0%    /var/audit
zroot/var/crash     zfs         2097152        96   2097056     0%    /var/crash
zroot/var/log       zfs         5238188      2904   5235284     0%    /var/log
zroot/var/mail      zfs          101544       172    101372     0%    /var/mail
zroot/var/tmp       zfs         2096336       220   2096116     0%    /var/tmp
zroot/vm            zfs        39315976  27266752  12049224    69%    /vm
[11:02][fmc000@tu45b-freebsd ~]

and these are the datasets that exist on my laptop:

[11:02][fmc000@tu45b-freebsd ~] $ zfs list|grep -v NAME|sort
zroot                198G   250G    96K  /zroot
[CODE]zroot/ROOT          13.2G   250G    96K  none
zroot/usr           7.21G   250G    96K  /usr
zroot/ROOT/default  13.2G   250G  10.7G  /
zroot/gdrive         133G  67.3G   133G  /gdrive
zroot/home          6.28G   250G    96K  /home
zroot/home/fmc000   6.28G  43.7G  3.20G  /home/fmc000
zroot/tmp            118M  4.89G  21.5M  /tmp
zroot/usr           7.21G   250G    96K  /usr
zroot/usr/ports     3.43G  41.6G  3.12G  /usr/ports
zroot/usr/src       3.78G  16.2G  1.16G  /usr/src
zroot/var           9.71M   250G    96K  /var
zroot/var/audit       96K  99.9M    96K  /var/audit
zroot/var/crash       96K  2.00G    96K  /var/crash
zroot/var/log       7.42M  4.99G  2.84M  /var/log
zroot/var/mail      1.00M  99.0M   172K  /var/mail
zroot/var/tmp       1.01M  2.00G   220K  /var/tmp
zroot/vm            38.5G  11.5G  26.0G  /vm
[11:02][fmc000@tu45b-freebsd ~] $

There are essentially two differences: these two datasets

zroot/ROOT          13.2G   250G    96K  none
zroot/usr           7.21G   250G    96K  /usr

are not mounted. The first looks normal to me but the second definitely does not.

I haven't changed much since my first installation last June (FreeBSD 14.1) - there are two custom datasets that I created and they show up correctly.

So my question is: why the zroot/usr is not mounted? Can/should I do something about it?

 

[eseipi]

So my question is: why the zroot/usr is not mounted? Can/should I do something about it?

This is normal because of boot environment layout. That way the entire content of your /usr directory actually resides under zroot/ROOT (because zroot/usr is not mounted), so it fall into the BE, with the exception of /usr/ports and /usr/src, which are on their own mounted datasets, so they are not part of the BE. See also "Boot Environment Structures" in bectl(8).

 

[T-Daemon]

The datasets appear to have been created by the FreeBSD installer installation script /usr/libexec/bsdinstall/zfsboot. This is the script being executed during a menu guided Root-on-ZFS installation. In this script, for "/usr" the property "canmount=off" is set in the default ZFS datasets creation.

140 # Default ZFS datasets for root zpool
141 #
142 # NOTE: Requires /tmp, /var/tmp, /$ZFSBOOT_BOOTFS_NAME/$ZFSBOOT_BOOTFS_NAME
143 # NOTE: Anything after pound/hash character [#] is ignored as a comment.
144 #
145 f_isset ZFSBOOT_DATASETS || ZFSBOOT_DATASETS="
146         # DATASET       OPTIONS (comma or space separated; or both)
147
148         # Boot Environment [BE] root and default boot dataset
149         /$ZFSBOOT_BEROOT_NAME                           mountpoint=none
150         /$ZFSBOOT_BEROOT_NAME/$ZFSBOOT_BOOTFS_NAME      mountpoint=/
151
152         # Home directories separated so they are common to all BEs
153         /home           mountpoint=/home
154
155         # Compress /tmp, allow exec but not setuid
156         /tmp            mountpoint=/tmp,exec=on,setuid=off
157
158         # Don't mount /usr so that 'base' files go to the BEROOT
159         /usr            mountpoint=/usr,canmount=off
160
161         # Ports tree
162         /usr/ports      setuid=off
163
164         # Source tree (compressed)
165         /usr/src
166
167         # Create /var and friends
168         /var            mountpoint=/var,canmount=off
169         /var/audit      exec=off,setuid=off
171         /var/log        exec=off,setuid=off
172         /var/mail       atime=on
173         /var/tmp        setuid=off
174 " # END-QUOTE

For BEROOT in comment see also "Boot Environment Structures" in bectl(8).

 

[fmc000]

Thank all, I learned something new today (and marked the thread as SOLVED )