Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 17 Jul 2022 17:42:07 +0100
From:      Graham Perrin <grahamperrin@freebsd.org>
To:        questions@freebsd.org
Subject:   zroot/ROOT/default, bectl(8) and boot environments (was: rationale for default ZFS datasets)
Message-ID:  <f771afba-2a43-d048-f9bc-d98de0e2000a@freebsd.org>
In-Reply-To: <CAKkGsYJKu9V6eveNSgs6783hz7dFnPGnh5C9cWnFqqJCgRzeDA@mail.gmail.com>
References:  <CAKkGsYJKu9V6eveNSgs6783hz7dFnPGnh5C9cWnFqqJCgRzeDA@mail.gmail.com>

next in thread | previous in thread | raw e-mail | index | archive | help
This is a multi-part message in MIME format.
--------------mT2Cei1nep2al0WjZqjQk0h2
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit

On 17/07/2022 17:28, Taceant Omnes wrote:
> … what is the purpose of zroot/ROOT/default? …

> root@fbsd-vm:~ # zfs list
> NAME                 USED  AVAIL     REFER  MOUNTPOINT
> zroot               4.38G  32.0G       96K  /zroot
> zroot/ROOT          3.40G  32.0G       96K  none
> zroot/ROOT/default  3.40G  32.0G     3.40G  /
> zroot/tmp           1001M  32.0G     1001M  /tmp
> zroot/usr            508K  32.0G       96K  /usr
> zroot/usr/home       220K  32.0G      148K  /usr/home
> zroot/usr/ports       96K  32.0G       96K  /usr/ports
> zroot/usr/src         96K  32.0G       96K  /usr/src
> zroot/var           1.02M  32.0G       96K  /var
> zroot/var/audit       96K  32.0G       96K  /var/audit
> zroot/var/crash       96K  32.0G       96K  /var/crash
> zroot/var/log        540K  32.0G      540K  /var/log
> zroot/var/mail       124K  32.0G      124K  /var/mail
> zroot/var/tmp         96K  32.0G       96K  /var/tmp

Consider the output from two commands:

zpool get bootfs zroot

zfs get mountpoint zroot/ROOT/default

If you find that the mountpoint is none, you might wonder about / in 
your listing above. This part of the magic of ZFS boot environments.

------------------------------------------------------------------------

Here, for example:

% zpool get bootfs august
NAME    PROPERTY  VALUE                              SOURCE
august  bootfs    august/ROOT/n256570-5c19fabbe34-e  local
% zfs get mountpoint august/ROOT/n256570-5c19fabbe34-e
NAME                               PROPERTY    VALUE       SOURCE
august/ROOT/n256570-5c19fabbe34-e  mountpoint  none        inherited 
from august
% bectl list -c creation
BE                        Active Mountpoint Space Created
n250511-5f73b3338ee-d     -      -          64.6G 2021-11-13 15:43
n253776-d5ad1713cc3-b     -      -          9.43G 2022-03-18 09:31
n254693-d7696096209-f     -      -          4.60G 2022-04-27 17:41
n255078-e140d551b78-h     -      -          88.4G 2022-05-11 21:18
n255588-01235012e5b-d     -      -          2.61G 2022-05-15 00:29
n255588-01235012e5b-b-c1d -      -          14.0G 2022-05-23 18:11
n255769-f16e38162c7-k     -      -          6.48G 2022-06-14 20:36
n256147-1c665e95d44-d     -      -          6.35G 2022-06-25 08:08
n256363-9c42645a1e4-d     -      -          3.32G 2022-07-05 19:40
n256570-5c19fabbe34-c     -      -          3.66M 2022-07-13 10:53
n256570-5c19fabbe34-d     -      -          80.8M 2022-07-16 08:00
n256570-5c19fabbe34-e     NR     /          61.9G 2022-07-17 12:09
%

See bectl(8) 
<https://www.freebsd.org/cgi/man.cgi?query=bectl&sektion=8&manpath=FreeBSD>;

--------------mT2Cei1nep2al0WjZqjQk0h2
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: 8bit

<html data-lt-installed="true">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
  </head>
  <body>
    <div class="moz-cite-prefix">On 17/07/2022 17:28, Taceant Omnes
      wrote:<br>
    </div>
    <blockquote type="cite"
cite="mid:CAKkGsYJKu9V6eveNSgs6783hz7dFnPGnh5C9cWnFqqJCgRzeDA@mail.gmail.com">
      <pre class="moz-quote-pre" wrap="">… what is the purpose of zroot/ROOT/default? …</pre>
    </blockquote>
    <br>
    <blockquote type="cite"
cite="mid:CAKkGsYJKu9V6eveNSgs6783hz7dFnPGnh5C9cWnFqqJCgRzeDA@mail.gmail.com">
      <pre class="moz-quote-pre" wrap="">root@fbsd-vm:~ # zfs list
NAME                 USED  AVAIL     REFER  MOUNTPOINT
zroot               4.38G  32.0G       96K  /zroot
zroot/ROOT          3.40G  32.0G       96K  none
zroot/ROOT/default  3.40G  32.0G     3.40G  /
zroot/tmp           1001M  32.0G     1001M  /tmp
zroot/usr            508K  32.0G       96K  /usr
zroot/usr/home       220K  32.0G      148K  /usr/home
zroot/usr/ports       96K  32.0G       96K  /usr/ports
zroot/usr/src         96K  32.0G       96K  /usr/src
zroot/var           1.02M  32.0G       96K  /var
zroot/var/audit       96K  32.0G       96K  /var/audit
zroot/var/crash       96K  32.0G       96K  /var/crash
zroot/var/log        540K  32.0G      540K  /var/log
zroot/var/mail       124K  32.0G      124K  /var/mail
zroot/var/tmp         96K  32.0G       96K  /var/tmp
</pre>
    </blockquote>
    <p>Consider the output from two commands: <br>
    </p>
    <p><font face="monospace">zpool get bootfs zroot</font></p>
    <p><font face="monospace">zfs get mountpoint zroot/ROOT/default</font></p>
    <p>If you find that the mountpoint is none, you might wonder about /
      in your listing above. This part of the magic of ZFS boot
      environments. <br>
    </p>
    <hr width="100%" size="2">
    <p>Here, for example: <br>
    </p>
    <p><span style="font-family:monospace"><span
          style="color:#000000;background-color:#ffffff;">% zpool get
          bootfs august
        </span><br>
        NAME    PROPERTY  VALUE                              SOURCE
        <br>
        august  bootfs    august/ROOT/n256570-5c19fabbe34-e  local
        <br>
        % zfs get mountpoint august/ROOT/n256570-5c19fabbe34-e
        <br>
        NAME                               PROPERTY    VALUE
              SOURCE
        <br>
        august/ROOT/n256570-5c19fabbe34-e  mountpoint  none
               inherited from august
        <br>
        % bectl list -c creation
        <br>
        BE                        Active Mountpoint Space Created
        <br>
        n250511-5f73b3338ee-d     -      -          64.6G 2021-11-13
        15:43
        <br>
        n253776-d5ad1713cc3-b     -      -          9.43G 2022-03-18
        09:31
        <br>
        n254693-d7696096209-f     -      -          4.60G 2022-04-27
        17:41
        <br>
        n255078-e140d551b78-h     -      -          88.4G 2022-05-11
        21:18
        <br>
        n255588-01235012e5b-d     -      -          2.61G 2022-05-15
        00:29
        <br>
        n255588-01235012e5b-b-c1d -      -          14.0G 2022-05-23
        18:11
        <br>
        n255769-f16e38162c7-k     -      -          6.48G 2022-06-14
        20:36
        <br>
        n256147-1c665e95d44-d     -      -          6.35G 2022-06-25
        08:08
        <br>
        n256363-9c42645a1e4-d     -      -          3.32G 2022-07-05
        19:40
        <br>
        n256570-5c19fabbe34-c     -      -          3.66M 2022-07-13
        10:53
        <br>
        n256570-5c19fabbe34-d     -      -          80.8M 2022-07-16
        08:00
        <br>
        n256570-5c19fabbe34-e     NR     /          61.9G 2022-07-17
        12:09
        <br>
        % <br>
        <br>
      </span>See <a moz-do-not-send="true"
href="https://www.freebsd.org/cgi/man.cgi?query=bectl&amp;sektion=8&amp;manpath=FreeBSD">bectl(8)</a></p>;
  </body>
  <lt-container></lt-container>
</html>

--------------mT2Cei1nep2al0WjZqjQk0h2--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?f771afba-2a43-d048-f9bc-d98de0e2000a>