Linux - General
Cockpit
dnf install cockpit systemctl enable --now cockpit.socket systemctl start --now cockpit.socket firewall-cmd --permanent --add-service=cockpit
Gnome
Window Manager
Bring back minimise/maximise buttons:
gsettings set org.gnome.desktop.wm.preferences button-layout ":minimize,maximize,close"
Power Settings
Fedora 38 changed default power settings. Per-user can be control in the control UI widget. For workstation edition, there is a default that applies at login screen (eg after reboot).
Check with:
sudo -u gdm dbus-run-session gsettings list-recursively org.gnome.settings-daemon.plugins.power | grep sleep
Set (eg to 1 hour) with:
sudo -u gdm dbus-run-session gsettings set org.gnome.settings-daemon.plugins.power sleep-inactive-ac-timeout 3600
To disable, set to 0.
OneDrive
Microsoft OneDrive sync:
- install package: onedrive
Authorization:
onedrive
and follow link to generate a login link to give back to onedrive.
- Storage in ~/OneDrive
- Configuration in ~/.config/onedrive
Show config:
onedrive --display-config
Dry run Synchronise:
onedrive --synchronize --dry-run --verbose
Synchronise:
onedrive --synchronize
Sync file list in ~/.config/ondrive/sync_list like:
# Demo /Security/*.kdbx !/Documents/Unwanted /Documents !/Temp
Then test:
onedrive --synchronize --dry-run --verbose
See also here
Grub
In /etc/default/grub, add to GRUB_CMDLINE_LINUX (GRUB_CMDLINE_XEN):
- dom0_mem=max:1024M dom0_max_vcpus=1
grub2-mkconfig -o /boot/grub2/grub.cfg
SELinux
getenforce setenforce 1 setenforce Enforcing sestatus
Show all boolean flags (state and default):
semanage boolean --list
Boolean flags:
getsebool -a setsebool -P httpd_read_user_content true setsebool -P httpd_enable_homedirs true
Interrogate SE policy:
sesearch --allow -s httpd_t -b httpd_enable_homedirs
systemd
Service Control
Basic use:
systemctl start something systemctl stop something systemctl enable something systemctl disable something
Service definition files in:
- /usr/lib/systemd/system
Deinitions with "@" names have argument passed as parameter, such as:
systemctl status clamd@scan
Show all defintions:
systemctl list-unit-files --type=service
Log Monitoring
All entries from boot time in UTC:
journalctl -b --utc
Show how many boots are recorded:
journalctl --list-boots
Time window:
journalctl --since "2022-01-01 00:50" --until yesterday journalctl --since 09:00 --until "1 hour ago"
Filter by unit (multiple -u options can be given):
journalctl -u httpd.service
Filter by UID/GID:
journalctl _UID=1000 _GID=1000
Do not page kernel messages:
journalctl -k --no-pager
SHow only 20 lines, or follow:
journalctl -20 journalctl -f
Stress-NG
Load CPU:
stress-ng --cpu 4 --timeout 60s --metrics
Swap
Add filesystem swap:
fallocate -l 1G /somepath/swap chmod 600 /somepath/swap mkswap /somepath/swap swapon /somepath/swap
Check:
swapon NAME TYPE SIZE USED PRIO /dev/sda2 partition 8G 219.8M -2 /somepath/swap file 1024M 0B -3
And then add a line to /etc/fstab to ensure it is enabled at boot:
/somepath/swap swap swap defaults 0 0
Timezone
Show available zones:
timedatectl list-timezones
Set and check:
timedatectl set-timezone timedatectl timedatectl
UDEV
See also: Udev and Udev Rules.
Custom rules files in /etc/udev/rules.d and must have .rules suffix, system rules live in /usr/lib/udev/rules.d. The are processed in lexographical order.
Display device attributes with:
udevadm info --query=env --name=/dev/sdg
Match the kernel assigned name for disk, and add (+=) a symlink with a new name "/dev/bigdata":
KERNEL=="sdb", SYMLINK+="bigdata"
Match PATH_ID from udevadm command, and add a symlink to a new name "/dev/database":
SUBSYSTEM=="block", ATTRS{ID_PATH}=="pci-0000:00:10.0-scsi-0:0:1:0", SYMLINK+="database"
Matching on ID_PART_TABLE_UUID is another candidate.
- Sepate multiple matches (==) with commas
- Single assignment (=) or append to list (+=).
Users / Accounts
Show password hashing algorithm:
authconfig --test | grep hashing
Set algorithm:
authconfig --passalgo=sha512 --update
Control password policy:
- /etc/security/pwquality.conf