Difference between revisions of "CentOS8 CheatSheet fuer System Administratoren"
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=SOS Report (Log Bundle)= | =SOS Report (Log Bundle)= | ||
This collects a log bundle which can be used for later debugging and analyzing. <br> | This collects a log bundle which can be used for later debugging and analyzing. <br> | ||
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sosreport | sosreport | ||
cp -av /var/tmp/sosreport* /root/ | cp -av /var/tmp/sosreport* /root/ | ||
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+ | ==Block Devices (Disks)== | ||
+ | * Show block uage of mounted disks | ||
+ | df -hP | ||
+ | |||
+ | * Show inode uage of mounted disks | ||
+ | df -hiP | ||
+ | |||
+ | * show how blockdevices are configured in system | ||
+ | lsblk | ||
+ | |||
+ | * Show memory statistics | ||
+ | free -th | ||
=Services= | =Services= | ||
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* list all service units | * list all service units | ||
systemctl list-unit-files | systemctl list-unit-files | ||
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=Events= | =Events= | ||
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+ | ==Show last boots== | ||
+ | journalctl --list-boots | ||
+ | last reboot | ||
==Journal== | ==Journal== | ||
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tail -f -n0 /var/log/* /var/log/*/* | tail -f -n0 /var/log/* /var/log/*/* | ||
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=CentOS 8 Stream migration= | =CentOS 8 Stream migration= | ||
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reboot | reboot | ||
+ | [[Category:Linux]] | ||
[[Category:ReferenceCards]] | [[Category:ReferenceCards]] | ||
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[[Category:Training]] | [[Category:Training]] |
Revision as of 15:05, 11 December 2020
Contents
1 SOS Report (Log Bundle)
This collects a log bundle which can be used for later debugging and analyzing.
Start this BEFORE you try to repair or change something, as well do not forget to snapshot/backup System/Application before debugging.
dnf -y install sos sosreport cp -av /var/tmp/sosreport* /root/
1.1 Block Devices (Disks)
- Show block uage of mounted disks
df -hP
- Show inode uage of mounted disks
df -hiP
- show how blockdevices are configured in system
lsblk
- Show memory statistics
free -th
2 Services
- list all service units
systemctl list-unit-files
- show all services in failed state
systemctl --all --state=failed
- show all running services
systemctl --all --state=running
- show detailed service status
systemctl start <svc-name>
- service handing
systemctl [start|stop|restart|enable|disable|mask] <svc-name>
- check if service is enabled to autostart after reboot
systemctl is-enabled <svc-name>
3 Events
3.1 Show last boots
journalctl --list-boots last reboot
3.2 Journal
- Follow all journal logs
journalctl -af
- Follow all journal logs with severity error or higher
journalctl --priority err --catalog --boot --follow
3.3 Log Files
- tail all currently open text files
lsof -F | sed '/^n\//!d;s/^n//;s/ .*//' | sort -u | xargs file | grep ' text$' | cut -d: -f1 | xargs tail -fn0
- tail all files under /var/log
tail -f -n0 /var/log/* /var/log/*/*
4 CentOS 8 Stream migration
CentOS8 will be discontinued by the Red Hat team. All the effort will go into CentOS Stream operating System which is a rolling release of CentOS.
You can directly migrate a CentOS8 into a CentOS8 Stream in place:
dnf install centos-release-stream dnf distro-sync cat /etc/centos-release reboot