Why can't I run programs after closing SSH connection using setsid, nohup or disown?

edwardliang2019

1/17/23, 1:30 AM

I am attempting to run a program 'a.o' on a remote server. To keep it running after closing SSH connection, I tried the following:

setsid ./a.o

nohup ./a.o

./a.o &
disown -h %1

None of these options seem to work, and I cannot figure out why. Any ideas on how to fix this problem?

P.S. I am using a tunnel connection to connect to the server via a jump machine. Also, this is a program that involves CUDA code running on GPU. Do these have anything to do with the issue?

0 + 0

ssh

bash

user535733

1/17/23, 1:41 AM

You can use a Terminal Multiplexer to keep processes running after logout. Both `screen` and `tmux` are quite good, and both are in the Ubuntu repositories.

edwardliang2019

1/17/23, 9:15 AM

@user535733 Thanks a lot. I tried tmux and it worked!

Score:1

Ubuntu

ThankYee

1/17/23, 4:41 AM

The nohup Wikipedia Page has a reference to this issue specifically:

Note that nohupping backgrounded jobs is typically used to avoid terminating them when logging off from a remote SSH session. A different issue that often arises in this situation is that ssh is refusing to log off ("hangs"), since it refuses to lose any data from/to the background job(s).[6][7] This problem can also be overcome by redirecting all three I/O streams:
$ nohup ./myprogram > foo.out 2> foo.err < /dev/null &
Also note that a closing SSH session does not always send a HUP signal to dependent processes, such as when a pseudo-terminal has not been allocated.

As mentioned in comments, screen and tmux are perfect for this too. Personally, I prefer tmux.

0 + 0

edwardliang2019

1/17/23, 9:14 AM

Thanks a lot! That solves my problem perfectly. And tmux works for me as well.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Why can't I run programs after closing SSH connection using setsid, nohup or disown?

TH: เหตุใดฉันจึงไม่สามารถเรียกใช้โปรแกรมหลังจากปิดการเชื่อมต่อ SSH โดยใช้ setid, nohup หรือ disown

RO: De ce nu pot rula programe după închiderea conexiunii SSH folosind setsid, nohup sau disown?

RU: Почему я не могу запускать программы после закрытия SSH-соединения с помощью setsid, nohup или disown?

VI: Tại sao tôi không thể chạy chương trình sau khi đóng kết nối SSH bằng setsid, nohup hoặc disown?

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.