Some ZFS questions

Frederic Chardon chardon.frederic at
Tue Apr 18 09:21:23 UTC 2017


Le 17 avr. 2017 20:42, "Andrea Venturoli" <ml at> a écrit :

zroot                781M  93.2G   144K  none
> zroot/ROOT           777M  93.2G   144K  none
> zroot/ROOT/default   777M  93.2G   777M  /
> zroot/tmp            176K  93.2G   176K  /tmp
> zroot/usr            616K  93.2G   144K  /usr
> zroot/usr/home       184K  93.2G   184K  /usr/home
> zroot/usr/ports      144K  93.2G   144K  /usr/ports
> zroot/usr/src        144K  93.2G   144K  /usr/src
> zroot/var           1.20M  93.2G   608K  /var
> zroot/var/crash      148K  93.2G   148K  /var/crash
> zroot/var/log        178K  93.2G   178K  /var/log
> zroot/var/mail       144K  93.2G   144K  /var/mail
> zroot/var/tmp        152K  93.2G   152K  /var/tmp

What puzzles me is "zroot/ROOT": why do we need that? Why do we mount
"zroot/ROOT/default" as root instead of simply mounting "zroot" at /?

It's a setup for Boot Environment (just google that ;)). If you install
sysutils/beadm you can then have in parallel several root fs. It's not
mandatory but so useful that's is enabled by default. The boot menu allow
you to choose from which root you want to boot. Personnaly I make a new BE
after each installworld and/or big port update (I put /usr/local and some
of /var inside the BE as well). If something break I have always a working
But it's really up to you.

This times I manually created the following structure:

> #zfs list
> NAME            ...     MOUNTPOINT
> zroot           ...     /
> zroot/usr       ...     /usr
> zroot/var       ...     /var

In fact, from a Live USB key, I can now simply issue "zpool import -R /mnt/
-f zroot" and I'll see all of my filesystems on /mnt.

Anything wrong with this setup?

Nothing wrong.

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