Timeline for How to check which SysRq functions are enabled?
Current License: CC BY-SA 3.0
16 events
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| May 11, 2020 at 1:09 | comment | added | ulidtko |
systemd-specific note: be sure to put the kernel.sysrq sysctl into a config /etc/sysctl.d/51-sysrq.conf with the prefix 51 or higher. That's because of /usr/lib/sysctl.d/50-default.conf — where they set kernel.sysrq = 16 (sic!). Check the priorities with sudo /usr/lib/systemd/systemd-sysctl --cat-config; reapply with sudo systemctl restart systemd-sysctl.service.
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| S Apr 10, 2018 at 22:00 | history | suggested | neverMind9 | CC BY-SA 3.0 |
Worth mentioning.
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| Apr 10, 2018 at 19:29 | review | Suggested edits | |||
| S Apr 10, 2018 at 22:00 | |||||
| S Dec 30, 2017 at 5:52 | history | suggested | Charley | CC BY-SA 3.0 |
updated link to kernel sysrq docs
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| Dec 30, 2017 at 0:29 | review | Suggested edits | |||
| S Dec 30, 2017 at 5:52 | |||||
| Jan 7, 2012 at 19:47 | comment | added | grawity_u1686 |
I did say 'many', not 'all' -- Debian/Ubuntu do keep it in /boot.
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| Jan 7, 2012 at 19:45 | comment | added | user001 |
Thanks @grawity. There is no file /proc/config.gz on my system, however.
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| Jan 7, 2012 at 19:16 | comment | added | grawity_u1686 |
On many Linux distros, the configuration is kept in the kernel itself, not in /boot, so the check command would be zgrep SYSRQ /proc/config.gz (or gunzip -c /proc/config.gz | grep SYSRQ).
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| Jan 7, 2012 at 18:28 | comment | added | user001 |
Thanks. Worked for me on Debian as well. The output: CONFIG_MAGIC_SYSRQ=y CONFIG_MAGIC_SYSRQ_DEFAULT_MASK=0x01b6 (01b6 in hex is 438 in decimal). I suppose the y means it has been enabled. Would give 2 up-votes if I could.
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| Jan 7, 2012 at 18:27 | comment | added | William Jackson |
I added a possible way to check for CONFIG_MAGIC_SYSRQ.
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| Jan 7, 2012 at 18:26 | history | edited | William Jackson | CC BY-SA 3.0 |
Added how to tell if CONFIG_MAGIC_SYSRQ is enabled
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| Jan 7, 2012 at 18:14 | comment | added | user001 |
One follow-up: If nothing happens when I do Alt+SysRq+(a command key), then I suppose this means that sysrq was not enabled when the kernel was installed. Is there a simple way to check whether sysrq is enabled or not (e.g., can I find the status of CONFIG_MAGIC_SYSRQ somewhere)?
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| Jan 7, 2012 at 18:12 | history | edited | William Jackson | CC BY-SA 3.0 |
Added conversion to base 2
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| Jan 7, 2012 at 18:09 | vote | accept | user001 | ||
| Jan 7, 2012 at 18:08 | comment | added | user001 | Ah, it's just a linear combination of the individual bitmasks. Thanks very much. | |
| Jan 7, 2012 at 18:05 | history | answered | William Jackson | CC BY-SA 3.0 |