[CRIU] Dumping tmux session with a client connected

[Cyrill Gorcunov]

On Mon, Apr 13, 2015 at 10:31:47AM -0700, Allan Cecil wrote:
...
>   733 ?        Ss     0:00 /usr/sbin/sshd -D
> 11788 ?        Ss     0:00  \_ sshd: ac [priv]     
> 11811 ?        S      0:01  |   \_ sshd: ac at pts/1      
> 11812 pts/1    Ss+    0:00  |       \_ -bash
> 16050 ?        Ss     0:00  \_ sshd: ac [priv]     
> 16070 ?        S      0:00  |   \_ sshd: ac at pts/2      
> 16071 pts/2    Ss+    0:00  |       \_ -bash
> 16411 ?        Ss     0:00  \_ sshd: ac [priv]     
> 16430 ?        S      0:00  |   \_ sshd: ac at pts/3      
> 16431 pts/3    Ss     0:00  |       \_ -bash
> 16447 pts/3    S+     0:00  |           \_ tmux
> 16448 pts/3    Z+     0:00  |               \_ [tmux] <defunct>
> 16465 ?        Ss     0:00  \_ sshd: ac [priv]     
> 16484 ?        S      0:00      \_ sshd: ac at pts/5      
> 16485 pts/5    Ss     0:00          \_ -bash
> 16499 pts/5    R+     0:00              \_ ps afx
>   779 ?        Ss     0:00 cron
>   809 tty1     Ss+    0:00 /sbin/getty -8 38400 tty1
>   816 ?        Ss     0:20 /usr/sbin/irqbalance
> 15349 ?        Ss     0:00 criu service -d
> 16449 ?        Ss     0:00 tmux
> 16450 pts/4    Ss     0:00  \_ -bash
> 16464 pts/4    S+     0:00      \_ top

So here are two tmux instances and sockets looks like socket from
firts tmux (16447) is sneaked into the tmux you're trying to dump.
If you run only one instance of tmux, does it help?

> ac at lbox:~$ ss -xup
> u_str  ESTAB      0      0                    * 52989                 * 52988   users:(("tmux",16447,4))
> u_str  ESTAB      0      0                    * 52997                 * 52996   users:(("tmux",16449,4))
> u_str  ESTAB      0      0                    * 52988                 * 52989   users:(("tmux",16447,3))
> u_str  ESTAB      0      0                    * 52996                 * 52997   users:(("tmux",16449,3))
> u_str  ESTAB      0      0                    * 52991                 * 52992   users:(("tmux",16447,6))
> u_str  ESTAB      0      0                    * 52992                 * 52991   users:(("tmux",16449,7))

> (00.000052) ========================================
> (00.000090) Dumping processes (pid: 16449)
...
> (00.020368) Dumping external sockets
> (00.020374) 	Dumping extern: ino 0xceff peer_ino 0xcf00 family    1 type    1 state  1 name (null)
> (00.020381) 	Dumped extern: id 0x22 ino 0xceff peer 0 type 2 state 10 name 0 bytes
> (00.020385) 	Ext stream not supported: ino 0xceff peer_ino 0xcf00 family    1 type    1 state  1 name (null)
> (00.020388) Error (sk-unix.c:564): Can't dump half of stream unix connection.