jails How to create a ubuntu jail？

Annalesa · 2026-02-21T15:15:16+0000

 ubuntu {

  exec.start = "/bin/sh /etc/rc";

  exec.stop = "/bin/sh /etc/rc.shutdown";

  exec.consolelog = "/var/log/jail_console_${name}.log";

  allow.raw_sockets;

  exec.clean;

  mount.devfs;

  host.hostname = "${name}";

  path = "/compat/ubuntu";

  ip4.addr = 1.1.1.5;

  interface = tap0;

}

 # service jail start ubuntu

Starting jails: cannot start jail  "ubuntu":

14

jail: ubuntu: getpwnam: No such file or directory

jail: ubuntu: /bin/sh /etc/rc: failed

skhal · 2026-02-21T15:44:45+0000

TLDR: does jail have /etc/master.passwd and password database?

I've stumbled upon the same issue recently when setting up an Alpine Linux jail. This thread helped me:

Solved Post in thread 'jail: getpwnam: No such file or directory'

Nov 12, 2019

SirDice said:
When you jexec(8) into the jail, do commands like getent passwd work?

Code:

# jexec gen5 getent passwd
jexec: jail "gen5" is dying

The solution from here (under "Troubleshooting Tips" section) works:

Code:

# cd /my/jail/path/etc
# echo "root::0:0::0:0:Charlie &:/root:/bin/bash" > master.passwd
# pwd_mkdb -d ./ -p master.passwd
pwd_mkdb: warning, unknown root shell

without need to run the subsequent commands they suggest:

Code:

# chroot /my/jail/path /bin/bash
# cd /etc
# pwconv
# grpconv
# passwd
Changing password for user root.
New password:
Retype new...

Annalesa · 2026-02-22T12:59:57+0000

skhal said:
TLDR: does jail have /etc/master.passwd and password database?

I've stumbled upon the same issue recently when setting up an Alpine Linux jail. This thread helped me:

Solved Post in thread 'jail: getpwnam: No such file or directory'

Nov 12, 2019

SirDice said:

When you jexec(8) into the jail, do commands like getent passwd work?

Click to expand...

Code:

# jexec gen5 getent passwd jexec: jail "gen5" is dying

The solution from here (under "Troubleshooting Tips" section) works:

Code:

# cd /my/jail/path/etc # echo "root::0:0::0:0:Charlie &:/root:/bin/bash" > master.passwd # pwd_mkdb -d ./ -p master.passwd pwd_mkdb: warning, unknown root shell

without need to run the subsequent commands they suggest:

Code:

# chroot /my/jail/path /bin/bash # cd /etc # pwconv # grpconv # passwd Changing password for user root. New password: Retype new...

aragats

Thanks, and how to solve the
jail: ubuntu: /bin/sh /etc/rc: failed problem?
I also tried /etc/init.d/rc, but it's same result.

jails How to create a ubuntu jail？

Annalesa

skhal

Solved Post in thread 'jail: getpwnam: No such file or directory'

Annalesa

Solved Post in thread 'jail: getpwnam: No such file or directory'