- Red Hat Enterprise Linux
- How do I disable MCE function?
- Why /var/log/mcelog file still has content even if I turn off mcelogd service?
- Add following item in
- From kernel-doc package:
Machine check Please see Documentation/x86/x86_64/machinecheck for sysfs runtime tunables. mce=off Disable machine check mce=no_cmci Disable CMCI(Corrected Machine Check Interrupt) that Intel processor supports. Usually this disablement is not recommended, but it might be handy if your hardware is misbehaving. Note that you'll get more problems without CMCI than with due to the shared banks, i.e. you might get duplicated error logs. mce=dont_log_ce Don't make logs for corrected errors. All events reported as corrected are silently cleared by OS. This option will be useful if you have no interest in any of corrected errors. mce=ignore_ce Disable features for corrected errors, e.g. polling timer and CMCI. All events reported as corrected are not cleared by OS and remained in its error banks. Usually this disablement is not recommended, however if there is an agent checking/clearing corrected errors (e.g. BIOS or hardware monitoring applications), conflicting with OS's error handling, and you cannot deactivate the agent, then this option will be a help. mce=bootlog Enable logging of machine checks left over from booting. Disabled by default on AMD because some BIOS leave bogus ones. If your BIOS doesn't do that it's a good idea to enable though to make sure you log even machine check events that result in a reboot. On Intel systems it is enabled by default. mce=nobootlog Disable boot machine check logging. mce=tolerancelevel[,monarchtimeout] (number,number) tolerance levels: 0: always panic on uncorrected errors, log corrected errors 1: panic or SIGBUS on uncorrected errors, log corrected errors 2: SIGBUS or log uncorrected errors, log corrected errors 3: never panic or SIGBUS, log all errors (for testing only) Default is 1 Can be also set using sysfs which is preferable. monarchtimeout: Sets the time in us to wait for other CPUs on machine checks. 0 to disable. nomce (for compatibility with i386): same as mce=off Everything else is in sysfs now.
- The cron job will regenerate mcelog in /var/log/mcelog in RHEL6, so just stop the mcelogd service is not enough.
After adding mce=off in the kernel parameter line, /usr/sbin/mcelog command cannot be run any more.
$ cat /etc/cron.hourly/mcelog.cron #!/bin/bash /usr/sbin/mcelog --ignorenodev --filter >> /var/log/mcelog
- systemd service will store the mcelog in RHEL7/8.
$ cat /etc/cron.hourly/mcelog.cron #!/bin/bash # Disabled by default on Fedora since this is run as daemon # using the mcelog.service systemd configuration entries. #/usr/sbin/mcelog --ignorenodev --filter >> /var/log/mcelog # systemctl status mcelog ● mcelog.service - Machine Check Exception Logging Daemon Loaded: loaded (/usr/lib/systemd/system/mcelog.service; enabled; vendor preset: enabled) Active: active (running) since Tue 2019-11-05 18:52:38 EST; 2 weeks 6 days ago Main PID: 1174 (mcelog) Tasks: 1 CGroup: /system.slice/mcelog.service └─1174 /usr/sbin/mcelog --ignorenodev --daemon --syslog Nov 05 18:52:38 testjay systemd: Starting Machine Check Exception Logging Daemon... Nov 05 18:52:38 testjay systemd: Started Machine Check Exception Logging Daemon.
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