This is a quick post about the steps I’m using to move my jails from one host to another. This is bing done as I merge two hosts into one. I have not attempted to automate this, apart from the initial syncoid copying of data. This post is base roughly upon my Mastodon post from yesterday.
In this post:
- FreeBSD 13.1
- sanoid-2.1.0
- copying from slocum
- copying to r730-01
- use of /etc/jail.conf.d/
Right, now, the jail I am copying is zm.
Here we go.
stop the jail
[slocum dan ~] % sudo service jail stop zm 18:28:49 Stopping jails: zm.
Then comment out that jail in /etc/jail.conf.
zm {
ip4.addr = "10.55.0.41";
}
Disable that IP address on the old host
In this case, the IP address is not assigned when the jail is started. It’s probably in /etc/rc.conf.
In addition to commenting out that line in that file, I also removed it from that host:
[slocum dan ~] % sudo ifconfig ix2 10.55.0.41/32 delete [slocum dan ~] %
That frees up the IP address to be used on the other host.
Create the new jail configuration
If you’re not using ansible, just use whatever you use for jail configuration.
In my ansible configuration, I added this file, roles/jail.conf.d/templates/zm.conf.j2. If you’re using ansible, the code is at https://git.langille.org/dvl/ansible/src/branch/main/jail.conf.d
{{ item }} {
{% include './templates/default_values.j2' %}
ip4.addr = "{{ host_nic }}|10.55.0.41";
}
As you can see, this IP address will be assigned to a NIC when the jail starts.
I added zm to this list in host_vars/r730-01.int.unixathome.org:
jails: - bacula - besser - certs - certs-rsync - cliff2 - git - pkg01 - svn - webserver - zm
Then I ran this command:
ansible-playbook jailhosts.yml --limit=r730-01.int.unixathome.org --tags=jail.conf.d
Now, over on the destination host, I have this file:
[r730-01 dvl /etc/jail.conf.d] % cat zm.conf 18:35:34
zm {
#
# start of standard settings for each jail
#
exec.start = "/bin/sh /etc/rc";
exec.stop = "/bin/sh /etc/rc.shutdown";
exec.clean;
exec.consolelog="/var/tmp/jail-console-$name.log";
mount.devfs;
path = /jails/$name;
allow.raw_sockets;
#securelevel = 2;
exec.prestart = "logger trying to start jail $name...";
exec.poststart = "logger jail $name has started";
exec.prestop = "logger shutting down jail $name";
exec.poststop = "logger jail $name has shut down";
host.hostname = "$name.int.unixathome.org";
persist;
#
# end of standard settings for each jail
#
ip4.addr = "igb0|10.55.0.41";
}
[r730-01 dvl /etc/jail.conf.d] % 18:37:11
One last sync
On the destination host, I ran this command as the syncoid user I created.
NOTE: I should have included the –preserve-recordsize parameter on this syncoid command. As it was, the received filesystem had the default recordsize of 128K. This might matter to you if you have set recordsize somewhere.
[syncoid@r730-01 ~]$ time syncoid --sshkey=~syncoid/.ssh/id_ed25519 -r --no-privilege-elevation syncoid@slocum.int.unixathome.org:system/jails/zm data02/jails/zm Sending incremental system/jails/zm@mkjail-202203272107 ... syncoid_r730-01.int.unixathome.org_2023-02-20:18:38:21-GMT00:00 (~ 5.2 GB): 5.31GiB 0:00:59 [90.9MiB/s] [===============================================] 102% cannot destroy snapshots: permission denied cannot destroy snapshots: permission denied WARNING: ssh -i ~syncoid/.ssh/id_ed25519 -S /tmp/syncoid-syncoid@slocum.int.unixathome.org-1676918300 syncoid@slocum.int.unixathome.org ' zfs destroy '"'"'system/jails/zm'"'"'@syncoid_r730-01.int.unixathome.org_2023-02-19:00:44:41-GMT00:00; zfs destroy '"'"'system/jails/zm'"'"'@syncoid_r730-01.int.unixathome.org_2023-02-18:23:48:01-GMT00:00' failed: 256 at /usr/local/bin/syncoid line 1380. real 1m1.255s user 0m16.104s sys 0m13.089s [syncoid@r730-01 ~]$
I don’t know why I’m getting cannot destroy snapshots: permission denied, but all seems well.
Add the jail to the list of what gets started
Because I’m using /etc/jail.conf.d/, as opposed to /etc/jail.conf, I’m adding the new jail to the list of jails to be started.
[r730-01 dvl /etc/jail.conf.d] % sysrc jail_list jail_list: pkg01 bacula besser certs-rsync certs cliff2 git svn webserver [r730-01 dvl /etc/jail.conf.d] % sudo sysrc jail_list+=zm jail_list: pkg01 bacula besser certs-rsync certs cliff2 git svn webserver -> pkg01 bacula besser certs-rsync certs cliff2 git svn webserver zm [r730-01 dvl /etc/jail.conf.d] %
mount the jail
Before I rebooted the host, I had to manually mount the jail filesystem which had just been copied over. However, now, since I have rebooted the host, for other reasons, I no longer have to do that step.
Check for other filesystems needed in this jail
On the sending host, I ran this command:
[slocum dan ~] % zfs list | grep zm system/jails/zm 4.97G 15.0T 2.18G /jails/zm
I was checking for other filesystems which might be mounted under /jails/zm. I found none.
Other jails, yet to be transferred, such as this one, have different results:
[slocum dan ~] % zfs list | grep stage-nginx01 nvd/freshports/stage-nginx01 30.1M 616G 24K none nvd/freshports/stage-nginx01/var 30.0M 616G 24K none nvd/freshports/stage-nginx01/var/db 30.0M 616G 24K none nvd/freshports/stage-nginx01/var/db/freshports 30.0M 616G 24K none nvd/freshports/stage-nginx01/var/db/freshports/cache 30.0M 616G 24K /var/db/freshports/cache nvd/freshports/stage-nginx01/var/db/freshports/cache/categories 41K 616G 26K /var/db/freshports/cache/categories nvd/freshports/stage-nginx01/var/db/freshports/cache/commits 29.0M 616G 29.0M /var/db/freshports/cache/commits nvd/freshports/stage-nginx01/var/db/freshports/cache/daily 38K 616G 24K /var/db/freshports/cache/daily nvd/freshports/stage-nginx01/var/db/freshports/cache/general 38K 616G 24K /var/db/freshports/cache/general nvd/freshports/stage-nginx01/var/db/freshports/cache/news 331K 616G 316K /var/db/freshports/cache/news nvd/freshports/stage-nginx01/var/db/freshports/cache/packages 24K 616G 24K /var/db/freshports/cache/packages nvd/freshports/stage-nginx01/var/db/freshports/cache/pages 38K 616G 24K /var/db/freshports/cache/pages nvd/freshports/stage-nginx01/var/db/freshports/cache/ports 422K 616G 406K /var/db/freshports/cache/ports nvd/freshports/stage-nginx01/var/db/freshports/cache/spooling 59K 616G 34K /var/db/freshports/cache/spooling system/jails/stage-nginx01 5.93G 15.0T 2.15G /jails/stage-nginx01 [slocum dan ~] %
If I was moving that jail, I’d also have to copy over
nvd/freshports/stage-nginx01
.
start the jail
This is me, starting the jail:
[r730-01 dvl /etc/jail.conf.d] % sudo service jail start zm Starting jails: zm.
All seems well. One to the next one.
