>
> I just tried to reproduce the same reload error on another LXC container
> which was upgraded from Debian 12 to 13 (Host running Debian 12) but here I
> did not get any errors.
>
> I have to dig deeper into this to find the differences.
>
It seems this is caused by the Systemd Unit "ssh.socket".
I noticed that on a newly installed Debian 13 LXC (using the "download"
template), the ssh.socket unit is enabled and active:
root@debian13:~# systemctl status ssh.socket
● ssh.socket - OpenBSD Secure Shell server socket
Loaded: loaded (/usr/lib/systemd/system/ssh.socket; enabled; preset:
enabled)
Active: active (listening) since Wed 2026-02-18 14:23:30 UTC; 1h 28min
ago
Invocation: 9615c912c29d45319a6124517c0f74f7
Triggers: ● ssh.service
Listen: [::]:22 (Stream)
Tasks: 0 (limit: 76096)
Memory: 8K (peak: 256K)
CPU: 328us
CGroup: /system.slice/ssh.socket
This triggers the ssh.service. On the other hand, the ssh.service unit
shows the "TriggeredBy" unit:
root@debian13:~# systemctl status ssh
● ssh.service - OpenBSD Secure Shell server
Loaded: loaded (/usr/lib/systemd/system/ssh.service; enabled; preset:
enabled)
Drop-In: /etc/systemd/system/ssh.service.d
└─override.conf
/run/systemd/system/service.d
└─zzz-lxc-service.conf
Active: active (running) since Wed 2026-02-18 15:50:31 UTC; 4s ago
Invocation: 5727506f7b9c4af0963036c0945e1658
TriggeredBy: ● ssh.socket
Docs: man:sshd(8)
man:sshd_config(5)
Process: 3165 ExecStartPre=/usr/sbin/sshd -t (code=exited,
status=0/SUCCESS)
Main PID: 3167 (sshd)
Tasks: 1 (limit: 76096)
Memory: 1.3M (peak: 2M)
CPU: 15ms
CGroup: /system.slice/ssh.service
└─3167 "sshd: /usr/sbin/sshd -D [listener] 0 of 10-100
startups"
The LXC container which were upgraded to Trixie don't show this. The
ssh.socket unit is disabled and there's no trigger in the ssh.service:
root@debian13upgraded:~# systemctl status ssh.socket
○ ssh.socket - OpenBSD Secure Shell server socket
Loaded: loaded (/usr/lib/systemd/system/ssh.socket; disabled; preset:
enabled)
Active: inactive (dead)
Triggers: ● ssh.service
Listen: [::]:22 (Stream)
root@debian13upgraded:~# systemctl status ssh
● ssh.service - OpenBSD Secure Shell server
Loaded: loaded (/usr/lib/systemd/system/ssh.service; enabled; preset:
enabled)
Active: active (running) since Wed 2026-02-18 15:20:59 CET; 1h 30min
ago
Invocation: bba7bd32e29d45199235a58c6790ebc2
Docs: man:sshd(8)
man:sshd_config(5)
Process: 25288 ExecStartPre=/usr/sbin/sshd -t (code=exited,
status=0/SUCCESS)
Main PID: 25291 (sshd)
Tasks: 3 (limit: 154378)
Memory: 4.8M (peak: 12.3M)
CPU: 22.706s
CGroup: /system.slice/ssh.service
├─25291 "sshd: /usr/sbin/sshd -D [listener] 1 of 10-100
startups"
├─35860 "sshd-session: unknown [priv]"
└─35861 "sshd-auth: unknown [net]"
I can reproduce the reload error on all the newly installed Debian 13
containers.
On all the upgraded Debian 13 containers the issue does not appear.
