How do I get systemd to kill sshd last during reboot? The 2019 Stack Overflow Developer Survey Results Are InHow to configure systemd journal-remote?How to check sshd log?Running multiple copies of openssh-server (sshd) on UbuntuHow to set environment variable in systemd service?Correctly setting the hostname - Fedora 20 on Amazon EC2LImiting overall memory usage for child processesHow to ensure sshd is the last service to be stopped during shutdown?Can't get systemd-networkd to start successfullyEasiest way to see linux memory usage when a process is killedremote server refuses connectionPreventing systemd start conditionally based on configuration
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How do I get systemd to kill sshd last during reboot?
The 2019 Stack Overflow Developer Survey Results Are InHow to configure systemd journal-remote?How to check sshd log?Running multiple copies of openssh-server (sshd) on UbuntuHow to set environment variable in systemd service?Correctly setting the hostname - Fedora 20 on Amazon EC2LImiting overall memory usage for child processesHow to ensure sshd is the last service to be stopped during shutdown?Can't get systemd-networkd to start successfullyEasiest way to see linux memory usage when a process is killedremote server refuses connectionPreventing systemd start conditionally based on configuration
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On a systemd machine (e.g. Debian), whenever I issue a reboot, among the very first things that get killed is sshd. This wasn't the case in the not-so-great-but-also-not-too-bad sysvinit days, where I could still watch and sometimes fix issues going wrong during a reboot via SSH.
I'd be fine with sshd to not get sent a TERM signal at all or ideally as one of the very last processes, even after network has been shut down. Is there a way to achieve this with systemd?
I'd also be interested in a way to make sshd get started as one of the first services, but that's less of a priority.
linux ssh systemd
asked Apr 7 at 22:11
al.al.
770517
add a comment |
On a systemd machine (e.g. Debian), whenever I issue a reboot, among the very first things that get killed is sshd. This wasn't the case in the not-so-great-but-also-not-too-bad sysvinit days, where I could still watch and sometimes fix issues going wrong during a reboot via SSH.
I'd be fine with sshd to not get sent a TERM signal at all or ideally as one of the very last processes, even after network has been shut down. Is there a way to achieve this with systemd?
I'd also be interested in a way to make sshd get started as one of the first services, but that's less of a priority.
linux ssh systemd
asked Apr 7 at 22:11
al.al.
770517
Is it Debian, or not-Debian? Because, Debian (and Ubuntu and other Debian derivatives) does many things (including systemd) very strangely, so you and the people who might answer this question must take that into account.
– Michael Hampton♦
Apr 8 at 0:10
I can't see the large strange differences wrt systemd between e.g. Debian and Arch Linux. For the question it really doesn't matter. I'm using Debian and Arch, but if there is a distro that behaves like I described, I'm happy to get a pointer to it and figure out myself what they're doing.
– al.
Apr 8 at 12:10
add a comment |
On a systemd machine (e.g. Debian), whenever I issue a reboot, among the very first things that get killed is sshd. This wasn't the case in the not-so-great-but-also-not-too-bad sysvinit days, where I could still watch and sometimes fix issues going wrong during a reboot via SSH.
I'd be fine with sshd to not get sent a TERM signal at all or ideally as one of the very last processes, even after network has been shut down. Is there a way to achieve this with systemd?
I'd also be interested in a way to make sshd get started as one of the first services, but that's less of a priority.
linux ssh systemd
asked Apr 7 at 22:11
al.al.
770517
On a systemd machine (e.g. Debian), whenever I issue a reboot, among the very first things that get killed is sshd. This wasn't the case in the not-so-great-but-also-not-too-bad sysvinit days, where I could still watch and sometimes fix issues going wrong during a reboot via SSH.
I'd be fine with sshd to not get sent a TERM signal at all or ideally as one of the very last processes, even after network has been shut down. Is there a way to achieve this with systemd?
I'd also be interested in a way to make sshd get started as one of the first services, but that's less of a priority.
linux ssh systemd
linux ssh systemd
asked Apr 7 at 22:11
al.al.
770517
asked Apr 7 at 22:11
al.al.
770517
edited Apr 7 at 22:35
al.
asked Apr 7 at 22:11
al.al.
770517
asked Apr 7 at 22:11
al.al.
770517
asked Apr 7 at 22:11
al.al.
770517
770517
Is it Debian, or not-Debian? Because, Debian (and Ubuntu and other Debian derivatives) does many things (including systemd) very strangely, so you and the people who might answer this question must take that into account.
– Michael Hampton♦
Apr 8 at 0:10
I can't see the large strange differences wrt systemd between e.g. Debian and Arch Linux. For the question it really doesn't matter. I'm using Debian and Arch, but if there is a distro that behaves like I described, I'm happy to get a pointer to it and figure out myself what they're doing.
– al.
Apr 8 at 12:10
add a comment |
Is it Debian, or not-Debian? Because, Debian (and Ubuntu and other Debian derivatives) does many things (including systemd) very strangely, so you and the people who might answer this question must take that into account.
– Michael Hampton♦
Apr 8 at 0:10
I can't see the large strange differences wrt systemd between e.g. Debian and Arch Linux. For the question it really doesn't matter. I'm using Debian and Arch, but if there is a distro that behaves like I described, I'm happy to get a pointer to it and figure out myself what they're doing.
– al.
Apr 8 at 12:10
Is it Debian, or not-Debian? Because, Debian (and Ubuntu and other Debian derivatives) does many things (including systemd) very strangely, so you and the people who might answer this question must take that into account.
– Michael Hampton♦
Apr 8 at 0:10
Is it Debian, or not-Debian? Because, Debian (and Ubuntu and other Debian derivatives) does many things (including systemd) very strangely, so you and the people who might answer this question must take that into account.
– Michael Hampton♦
Apr 8 at 0:10
I can't see the large strange differences wrt systemd between e.g. Debian and Arch Linux. For the question it really doesn't matter. I'm using Debian and Arch, but if there is a distro that behaves like I described, I'm happy to get a pointer to it and figure out myself what they're doing.
– al.
Apr 8 at 12:10
I can't see the large strange differences wrt systemd between e.g. Debian and Arch Linux. For the question it really doesn't matter. I'm using Debian and Arch, but if there is a distro that behaves like I described, I'm happy to get a pointer to it and figure out myself what they're doing.
– al.
Apr 8 at 12:10
add a comment |
1 Answer
1
active
oldest
votes
What are you going to observe and accomplish in 2 seconds? That is the time I observe a shutdown taking in its entirety: from terminating services, ifdown interfaces, unmount file systems, and TERM all processes. I tested with Debian Stretch on Google Cloud, built on 20190326.
Stopping services takes out their slices, and it is done in parallel. Their process tree including your sessions are rapidly terminated. I'm not aware of a configuration that will output anything useful before your session is gone.
You can have events logged via journald with Storage=persistent, or possibly sent to a remote system with systemd-journal-remote. Logs from the previous boot can be retrieved with journalctl -b -1. Either get back on the rebooted system with ssh or console, or look at remote logs.
answered Apr 8 at 13:57
John MahowaldJohn Mahowald
8,7131713
1
I think he is referring to the situation when something goes wrong during shutdown (which does happen occasionally).
– Michael Hampton♦
Apr 8 at 13:59
Then console access (hypervisor, BMC) to the host, check the journal, fix things, and forcibly power it off if necessary. What recovery is possible depends on which failure mode. I have yet to see one where sessions still survive but shutdown failed.
– John Mahowald
Apr 8 at 14:20
Michael Hampton is correct, I'm trying to debug embedded systems that don't reliably shut down and have no persistent logging by default. I can add a console on demand, but that doesn't scale. This type of debugging was never a problem with sysvinit. Remote journal is an option, thanks for suggesting.
– al.
2 days ago
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
What are you going to observe and accomplish in 2 seconds? That is the time I observe a shutdown taking in its entirety: from terminating services, ifdown interfaces, unmount file systems, and TERM all processes. I tested with Debian Stretch on Google Cloud, built on 20190326.
Stopping services takes out their slices, and it is done in parallel. Their process tree including your sessions are rapidly terminated. I'm not aware of a configuration that will output anything useful before your session is gone.
You can have events logged via journald with Storage=persistent, or possibly sent to a remote system with systemd-journal-remote. Logs from the previous boot can be retrieved with journalctl -b -1. Either get back on the rebooted system with ssh or console, or look at remote logs.
answered Apr 8 at 13:57
John MahowaldJohn Mahowald
8,7131713
1
I think he is referring to the situation when something goes wrong during shutdown (which does happen occasionally).
– Michael Hampton♦
Apr 8 at 13:59
Then console access (hypervisor, BMC) to the host, check the journal, fix things, and forcibly power it off if necessary. What recovery is possible depends on which failure mode. I have yet to see one where sessions still survive but shutdown failed.
– John Mahowald
Apr 8 at 14:20
Michael Hampton is correct, I'm trying to debug embedded systems that don't reliably shut down and have no persistent logging by default. I can add a console on demand, but that doesn't scale. This type of debugging was never a problem with sysvinit. Remote journal is an option, thanks for suggesting.
– al.
2 days ago
add a comment |
What are you going to observe and accomplish in 2 seconds? That is the time I observe a shutdown taking in its entirety: from terminating services, ifdown interfaces, unmount file systems, and TERM all processes. I tested with Debian Stretch on Google Cloud, built on 20190326.
Stopping services takes out their slices, and it is done in parallel. Their process tree including your sessions are rapidly terminated. I'm not aware of a configuration that will output anything useful before your session is gone.
You can have events logged via journald with Storage=persistent, or possibly sent to a remote system with systemd-journal-remote. Logs from the previous boot can be retrieved with journalctl -b -1. Either get back on the rebooted system with ssh or console, or look at remote logs.
answered Apr 8 at 13:57
John MahowaldJohn Mahowald
8,7131713
1
I think he is referring to the situation when something goes wrong during shutdown (which does happen occasionally).
– Michael Hampton♦
Apr 8 at 13:59
Then console access (hypervisor, BMC) to the host, check the journal, fix things, and forcibly power it off if necessary. What recovery is possible depends on which failure mode. I have yet to see one where sessions still survive but shutdown failed.
– John Mahowald
Apr 8 at 14:20
Michael Hampton is correct, I'm trying to debug embedded systems that don't reliably shut down and have no persistent logging by default. I can add a console on demand, but that doesn't scale. This type of debugging was never a problem with sysvinit. Remote journal is an option, thanks for suggesting.
– al.
2 days ago
add a comment |
What are you going to observe and accomplish in 2 seconds? That is the time I observe a shutdown taking in its entirety: from terminating services, ifdown interfaces, unmount file systems, and TERM all processes. I tested with Debian Stretch on Google Cloud, built on 20190326.
Stopping services takes out their slices, and it is done in parallel. Their process tree including your sessions are rapidly terminated. I'm not aware of a configuration that will output anything useful before your session is gone.
You can have events logged via journald with Storage=persistent, or possibly sent to a remote system with systemd-journal-remote. Logs from the previous boot can be retrieved with journalctl -b -1. Either get back on the rebooted system with ssh or console, or look at remote logs.
answered Apr 8 at 13:57
John MahowaldJohn Mahowald
8,7131713
What are you going to observe and accomplish in 2 seconds? That is the time I observe a shutdown taking in its entirety: from terminating services, ifdown interfaces, unmount file systems, and TERM all processes. I tested with Debian Stretch on Google Cloud, built on 20190326.
Stopping services takes out their slices, and it is done in parallel. Their process tree including your sessions are rapidly terminated. I'm not aware of a configuration that will output anything useful before your session is gone.
You can have events logged via journald with Storage=persistent, or possibly sent to a remote system with systemd-journal-remote. Logs from the previous boot can be retrieved with journalctl -b -1. Either get back on the rebooted system with ssh or console, or look at remote logs.
answered Apr 8 at 13:57
John MahowaldJohn Mahowald
8,7131713
answered Apr 8 at 13:57
John MahowaldJohn Mahowald
8,7131713
answered Apr 8 at 13:57
John MahowaldJohn Mahowald
8,7131713
answered Apr 8 at 13:57
John MahowaldJohn Mahowald
8,7131713
8,7131713
1
I think he is referring to the situation when something goes wrong during shutdown (which does happen occasionally).
– Michael Hampton♦
Apr 8 at 13:59
Then console access (hypervisor, BMC) to the host, check the journal, fix things, and forcibly power it off if necessary. What recovery is possible depends on which failure mode. I have yet to see one where sessions still survive but shutdown failed.
– John Mahowald
Apr 8 at 14:20
Michael Hampton is correct, I'm trying to debug embedded systems that don't reliably shut down and have no persistent logging by default. I can add a console on demand, but that doesn't scale. This type of debugging was never a problem with sysvinit. Remote journal is an option, thanks for suggesting.
– al.
2 days ago
add a comment |
1
I think he is referring to the situation when something goes wrong during shutdown (which does happen occasionally).
– Michael Hampton♦
Apr 8 at 13:59
Then console access (hypervisor, BMC) to the host, check the journal, fix things, and forcibly power it off if necessary. What recovery is possible depends on which failure mode. I have yet to see one where sessions still survive but shutdown failed.
– John Mahowald
Apr 8 at 14:20
Michael Hampton is correct, I'm trying to debug embedded systems that don't reliably shut down and have no persistent logging by default. I can add a console on demand, but that doesn't scale. This type of debugging was never a problem with sysvinit. Remote journal is an option, thanks for suggesting.
– al.
2 days ago
1
1
I think he is referring to the situation when something goes wrong during shutdown (which does happen occasionally).
– Michael Hampton♦
Apr 8 at 13:59
I think he is referring to the situation when something goes wrong during shutdown (which does happen occasionally).
– Michael Hampton♦
Apr 8 at 13:59
Then console access (hypervisor, BMC) to the host, check the journal, fix things, and forcibly power it off if necessary. What recovery is possible depends on which failure mode. I have yet to see one where sessions still survive but shutdown failed.
– John Mahowald
Apr 8 at 14:20
Then console access (hypervisor, BMC) to the host, check the journal, fix things, and forcibly power it off if necessary. What recovery is possible depends on which failure mode. I have yet to see one where sessions still survive but shutdown failed.
– John Mahowald
Apr 8 at 14:20
Michael Hampton is correct, I'm trying to debug embedded systems that don't reliably shut down and have no persistent logging by default. I can add a console on demand, but that doesn't scale. This type of debugging was never a problem with sysvinit. Remote journal is an option, thanks for suggesting.
– al.
2 days ago
Michael Hampton is correct, I'm trying to debug embedded systems that don't reliably shut down and have no persistent logging by default. I can add a console on demand, but that doesn't scale. This type of debugging was never a problem with sysvinit. Remote journal is an option, thanks for suggesting.
– al.
2 days ago
add a comment |
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Is it Debian, or not-Debian? Because, Debian (and Ubuntu and other Debian derivatives) does many things (including systemd) very strangely, so you and the people who might answer this question must take that into account.
– Michael Hampton♦
Apr 8 at 0:10
I can't see the large strange differences wrt systemd between e.g. Debian and Arch Linux. For the question it really doesn't matter. I'm using Debian and Arch, but if there is a distro that behaves like I described, I'm happy to get a pointer to it and figure out myself what they're doing.
– al.
Apr 8 at 12:10