Hi,
I have a small issue with thinjails set up according to the FreeBSD handbook ( https://docs.freebsd.org/en/books/handbook/jails/ ).
For some reason the root nullfs mountpoint of the jail does not get unmounted after stopping it with
Therefore the jail cannot be started again:
My setup is the following:
This is a jail I just created from the template I made according to the handbook.
I know I could just use exec.prestop to unmount the nullfs base, but something in the process of stopping the jails seems to be wrong here.
Actually I have another jail in which I try to run nfsd which also does not stop as it should - that nfsd jail goes to the "dying" state when I try to stop it and does not release the vnet device, and I have to reboot the host to resolve this situation.
Since this basic jail already exhibits an issue when beeing stopped, I would like to resolve that first and see if it also resolves the issue with the other jail.
As always, any help would be very much appreciated!
Edit: I'm running FreeBSD 15.0-RELEASE-p5 .
I have a small issue with thinjails set up according to the FreeBSD handbook ( https://docs.freebsd.org/en/books/handbook/jails/ ).
For some reason the root nullfs mountpoint of the jail does not get unmounted after stopping it with
Code:
service jail onestop thinjail
Code:
# service jail onestart thinjail
Starting jails: cannot start jail "thinjail":
mount_nullfs: /jail/nullfs-base/thinjail: Resource deadlock avoided
jail: thinjail: /sbin/mount -t nullfs -o ro /jail/templates/freebsd-base /jail/nullfs-base/thinjail: failed
.My setup is the following:
Code:
zroot/jail 884M 183G 158M /jail
zroot/jail/containers 352M 183G 112K /jail/containers
zroot/jail/containers/thinjail 188K 183G 5.41M /jail/containers/thinjail
zroot/jail/templates 374M 183G 96K /jail/templates
zroot/jail/templates/freebsd-base 369M 183G 369M /jail/templates/freebsd-base
zroot/jail/templates/freebsd-overlay 5.42M 183G 5.33M /jail/templates/freebsd-overlay
Code:
# ls -lh /jail/containers/thinjail/
total 35 KB
drwxr-xr-x 30 root wheel 108B Apr 6 14:57 etc
drwxr-xr-x 2 root wheel 2B Mar 26 20:36 home
drwxr-x--- 2 root wheel 8B Apr 6 14:57 root
drwxr-xr-x 24 root wheel 24B Apr 6 14:57 tmp
drwxr-xr-x 3 root wheel 3B Mar 26 21:16 usr
drwxr-xr-x 24 root wheel 24B Nov 28 04:42 var
# ls -lh /jail/templates/freebsd-base/
total 78 KB
-r--r--r-- 1 root wheel 5.9K Nov 28 04:51 COPYRIGHT
drwxr-xr-x 2 root wheel 49B Mar 26 20:30 bin
drwxr-xr-x 15 root wheel 71B Mar 26 20:30 boot
dr-xr-xr-x 2 root wheel 2B Nov 28 04:42 dev
lrwxr-xr-x 1 root wheel 11B Apr 4 17:08 etc -> overlay/etc
lrwxr-xr-x 1 root wheel 12B Apr 4 17:08 home -> overlay/home
drwxr-xr-x 4 root wheel 80B Mar 26 20:30 lib
drwxr-xr-x 3 root wheel 8B Nov 28 04:43 libexec
drwxr-xr-x 2 root wheel 2B Nov 28 04:42 media
drwxr-xr-x 2 root wheel 2B Nov 28 04:42 mnt
drwxr-xr-x 2 root wheel 2B Nov 28 04:42 net
drwxr-xr-x 2 root wheel 2B Mar 26 20:42 overlay
dr-xr-xr-x 2 root wheel 2B Nov 28 04:42 proc
drwxr-xr-x 2 root wheel 152B Mar 26 20:30 rescue
lrwxr-xr-x 1 root wheel 12B Apr 4 17:08 root -> overlay/root
drwxr-xr-x 2 root wheel 150B Mar 26 20:30 sbin
lrwxr-xr-x 1 root wheel 11B Nov 28 04:42 sys -> usr/src/sys
drwxr-xr-x 2 root wheel 2B Apr 6 13:33 tmp
drwxr-xr-x 13 root wheel 14B Apr 4 17:09 usr
lrwxr-xr-x 1 root wheel 11B Apr 4 17:08 var -> overlay/tmp
Code:
# cat /etc/jail.conf.d/thinjail.conf
thinjail {
# PERMISSIONS
devfs_ruleset="5";
enforce_statfs="1"; # needed to allow file system mounts below jail root
allow.raw_sockets;
allow.reserved_ports;
mount.devfs;
vnet;
vnet.interface = "iavf0";
# STARTUP/LOGGING
exec.start = "/bin/sh /etc/rc";
exec.stop = "/bin/sh /etc/rc.shutdown";
exec.poststop = "";
exec.consolelog = "/var/log/jail_console_${name}.log";
exec.clean;
# HOSTNAME/PATH
host.hostname = "${name}";
path = "/jail/nullfs-base/${name}";
# MOUNT
mount.fstab = "/jail/${name}.fstab";
}
Code:
# cat /jail/thinjail.fstab
/jail/templates/freebsd-base /jail/nullfs-base/thinjail nullfs ro 0 0
/jail/containers/thinjail /jail/nullfs-base/thinjail/overlay nullfs rw 0 0
tmpfs /jail/nullfs-base/thinjail/tmp tmpfs rw,mode=777,size=512M 0 0
Code:
# cat /var/log/jail_console_thinjail.log
ELF ldconfig path: /lib /usr/lib /usr/lib/compat
32-bit compatibility ldconfig path: /usr/lib32
Starting Network: lo0 iavf0.
lo0: flags=1008049<UP,LOOPBACK,RUNNING,MULTICAST,LOWER_UP> metric 0 mtu 16384
options=680003<RXCSUM,TXCSUM,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
inet 127.0.0.1 netmask 0xff000000
inet6 ::1 prefixlen 128
inet6 fe80::1%lo0 prefixlen 64 scopeid 0xc
groups: lo
nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
iavf0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
options=4e507bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,VLAN_HWFILTER,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
ether 3c:fd:fe:d5:98:f2
inet 10.0.7.12 netmask 0xffffff00 broadcast 10.0.7.255
media: Ethernet autoselect (1000baseT <full-duplex>)
status: active
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
route: message indicates error: File exists
add host 127.0.0.1: gateway lo0 fib 0: route already in table
add net default: gateway 10.0.7.1
route: message indicates error: File exists
add host ::1: gateway lo0 fib 0: route already in table
add net fe80::: gateway ::1
add net ff02::: gateway ::1
add net ::ffff:0.0.0.0: gateway ::1
add net ::0.0.0.0: gateway ::1
Updating motd:.
Creating and/or trimming log files.
Clearing /tmp (X related).
Updating /var/run/os-release done.
Starting syslogd.
Starting cron.
Mon Apr 6 14:57:34 CEST 2026
Stopping cron.
Waiting for PIDS: 4933.
.
TerminatedThis is a jail I just created from the template I made according to the handbook.
I know I could just use exec.prestop to unmount the nullfs base, but something in the process of stopping the jails seems to be wrong here.
Actually I have another jail in which I try to run nfsd which also does not stop as it should - that nfsd jail goes to the "dying" state when I try to stop it and does not release the vnet device, and I have to reboot the host to resolve this situation.
Since this basic jail already exhibits an issue when beeing stopped, I would like to resolve that first and see if it also resolves the issue with the other jail.
As always, any help would be very much appreciated!
Edit: I'm running FreeBSD 15.0-RELEASE-p5 .
