Skillnad mellan versioner av "Generic-cli"
Js146669 (Diskussion | bidrag) (→RPM) |
Js146669 (Diskussion | bidrag) (→RPM) |
||
| Rad 87: | Rad 87: | ||
Display all configuration files for a pkg | Display all configuration files for a pkg | ||
# rpm -qc yum cfg files | # rpm -qc yum cfg files | ||
| − | Display all | + | Display all docs for a command |
# rpm -qdf /bin/bash | # rpm -qdf /bin/bash | ||
Display which pkgs install bash | Display which pkgs install bash | ||
| Rad 100: | Rad 100: | ||
# rpm -qlp <pkgname> | # rpm -qlp <pkgname> | ||
'''OBS!''' the ‘p’ option queries a downloaded pkg and not the repo database. | '''OBS!''' the ‘p’ option queries a downloaded pkg and not the repo database. | ||
| − | |||
| − | |||
'''RPM TAGS''' | '''RPM TAGS''' | ||
Versionen från 11 maj 2021 kl. 16.26
Innehåll
Manpages
Display the different manpages for a command.
$ man -f <cmd to find>
Perform an extensive search for a manpage
$ man -k <cmd to find>
N.B!Info pages support hyperlinks, manpages do not.
Disks/PV/VG/LV info
Display a more readable output of disks/vols/mountpoints on Linux
# lsblk -i
Physical Volumes
# pvscan # pvdisplay
Volume Groups
# vgscan # vgdisplay # vgchange # vgrename # vgs
Logical Volumes
# lvscan # lgscan # lvdisplay # lvchange # lvs # lvresize # lvextend # lvreduce # lvrename
Rename Root Vol
To change the root vol name, boot from a bootable ISO or CDROM
Login and run the following
# vgrename <old-vg> <new-vg>
Mount the root disk & required sub filesystems
# mount /dev/<new-vg> /mnt # mount --bind /proc /mnt/proc/ # mount --bind /sys /mnt/sys/ # mount --bind /dev /mnt/dev/ # mount /dev/sda1 /mnt/boot/ # chroot /mnt
Edit the fstab and grub files
# sed -i 's/<old-vg>/<new-vg>/g' /etc/fstab # sed -i 's/<old-vg>/<new-vg>/g' /etc/default/grub
Use grub2-mkconfig
# grub2-mkconfig -o /boot/grub/grub.cfg
Create new kernel initramfs/initrd image file using a specific kernel version.
# dracut --force --kver <choose kernel vers>
Tips! Run <uname -r > to show the active kernel version or check for different versions in </boot> for required kernel name.
Use the following to check content of new initramfs/initrd image
List entire content # lsinitrd <path-to-image> View a specific file from the image file # lsinitrd -f /etc/fstab <path-to-image>
unmount chroot & reboot
# umount -f /mnt # shutdown -h now
Remove cdrom/ISO and reboot.
RPM
Find out what pkg a file belongs to
# rpm -qf <path-to-file/cmd>
Find out if a file was installed as part of a pkg
# rpm -ql /usr/liblibXp.so.6
List path to files for yum
# rpm -ql yum
Display system-wide config files for a cmd
# rpm -qcf /bin/bash
Check contents of RPM
# rpm -qlp RPMTOPDIR/RPMS/x86_64/<name-of-pkg>.rpm
To view different architecture version of a pkg
# rpm -q --queryformat "%{name}.%{arch}\n" pdksh-5.2.14-36.el5
Display a pkg group
# rpm -qa Group=“System Environment/Shells”
Display when pkgs installed
# rpm -qa last
Display all dokumentation for a pkg
# rpm -qd yum dok files
Display all configuration files for a pkg
# rpm -qc yum cfg files
Display all docs for a command
# rpm -qdf /bin/bash
Display which pkgs install bash
# rpm -q --provides bash
Display dependencies on the bash pkg
# rpm -q --requires bash
Display all changes made to pkg
# rpm -q --changelog bash
Display info about a specific package.
# rpm -qip <pkgname>
Display info about files to be installed from a pkg
# rpm -qlp <pkgname>
OBS! the ‘p’ option queries a downloaded pkg and not the repo database.
RPM TAGS
Display all pkg tags in OS vesion
$ rpm --querytags
Display the permission modes of all files in the bash package
$ rpm -q --qf “[%{FILEMODES} %{FILENAMES}\n]” bash
To format the permissions better, We can add the perms formatting modifier.
$ rpm -q --qf “[%{FILEMODES:perms} %{FILENAMES}\n]” bash
N.B! To display a list of other query format modifiers use the RPM manpage and search for query options.
GREP
grep for soltec in start of line
# grep ^"soltec"
grep for soltec at end of line
# grep "soltec"$
Ignore all systemd messages
# grep -v ‘systemd’ /var/log/messages -v for invert
Ignore multiple expressions using egrep
# egrep -v ‘systemd|NetworkManager’ /var/log/messages
YUM
to install all pkgs in listed in file
# yum install $(< test.txt) # yum -y install $(cat list)
Display history
# yum history # yum history info # yum history list
Configure & use YUM to download packages to local repo
Create a dir $ mkdir /tmp/yumdownloads Install the yum Download-only plugin $ yum -y install -y yum-plugin-downloadonly Execute YUM to download pkg(s) $ yum install - -downloadonly --downloaddir=/tmp/yumdownloads httpd
DNF
YUM has been rewritten and named DNF. YUM is legacy and can be executed as it uses DNF.
DNF can use software groups to install all pkgs required e.g. desktop, development tools…mm
$ dnf group list $ dnf group list hidden $ dnf group info “Development Tools”
Display all versions of a pkg
$ dnf --showduplicates list xfsprogs
Display pkgs that have upgrades available
$ dnf list --updates
Upgrade a pkg (find pkg from updates command)
$ dnf upgrade <pkgname>
Display pkgs that are available in the repo but not installed
$ dnf list --available
Display pkgs that have been replaced by other packages
$ dnf list --obsoletes
Display pkgs dependencies
$ dnf deplist <pkgname>
Search for a package
$ dnf search <search string>
To search even in pkg metadata
$ dnf search all <search string>
Display which pkgs utilise a specific command
$ dnf provides <cmd string>
Install a pkg over an existing pkg (similar to upgrading)
$ dnf reinstall <pkgname>
Remove any unused dependencies in system i.e. if not used by other pkgs
$ dnf autoremove
Remove a package and dependencies i.e. if not used by other pkgs
$ dnf autoremove <pkgname>
Disable a pkg from being upgraded by installing version lock plugin
$ dnf install python3-dnf-plugin-versionlock
To lock a specific kernel version
$ dnf versionlock add <kernel-version>
To lock the current kernel version
$ dnf versionlock add kernel
Display pkgs that are versionlocked
$ dnf versionlock list
Clear pkgs that are versionlocked
$ dnf versionlock clear
$ dnf versionlock delete <locked pkg from list output>
- Configuration files may be renamed when a new package is installed.
- If the system administrator has not modified a configuration file, then the config file is overwritten.
- If the system administrator has modified the configuration file, then the modified configuration file is saved with a ,rpmsave or .rpmorig extension. And the new configuration file is saved from the package.
- The .rpmsave extension is used if the file was installed from a previous rpm package.
- The .rpmorig extension is used if the file came from a non-rpm source. This would happen if you installed from source code and then later moved on to an rpm package.
- If the administrator has modified the configuration file, and the software package maintainer included the noreplace label in the package, then the new configuration file is saved with a .rpmnew extension and the original configuration is left in place. When installing with dnf and rpm, you will see a message to let you know which operation was done.
$ dnf changelog
$ dnf changelog upgrades
VI
dG |delete from line to end of file d1G |delete to top including current line dgg |delete from line to start of file G |goto last line in file 1G |to to first line in file 0 |goto start of line $ |goto end of line :set number |to display line numbers :color desert |to change display colours ctrl r |undo changes cl, cw, cc |cut letter, word, line yl, yw, yy |yank letter, word, line dl, dw, dd |delete letter, word, line
Copy/Move data
To move data on the same system, use the following:
# cd dir1 && tar -cf - . | (cd dir2 && tar -xpvf -)
dir1 is the directory you want to copy. dir2 is the directory in which you want the copy to go. This tar’s the current directory to STDOUT, then changes directory, and untar’s the archive without ever having to find the space for a .tar file.
Use the following to do this across systems via ssh:
# cd dir1 && tar -cf - . | ssh system2 "cd dir2 && tar -xpvf -"
RSYNC Slash or no Slash
- Without a slash on the source directory means copy both the source directory, and the contents (recursively if specified) to the destination directory
- Adding a trailing slash on the SRC directory means only copy the contents of the SRC directory, recursively if specified, to the destination.
RSYNC v RSYNCD
Use rysncd instead of rsync to use resources on the target system copying the data instead of source server
TOP
The top program provides a dynamic real-time view of a running system. It can display system summary information as well as a list of tasks currently being managed by the Linux kernel.
Executing on the cli
Usage: top -hv | -bcHiOSs -d secs -n max -u|U user -p pid(s) -o field -w [cols]
# top # top –u dbuser | option will display specific User process details # top -n 1 -b > top-output.txt | save the running top command results output to a file # top -n 10 |automatically exit after 10 number of repetition.
Reading the output
N.B! By default, top updates its display every three seconds
- The first line of numbers on the dashboard includes the time, how long your computer has been running, the number of people logged in, and what the load average has been for the past one, five, and 15 minutes.
- The second line shows the number of tasks and their states: running, stopped, sleeping, or zombie.
- The third line displays the following central processing unit (CPU) values:
us: Amount of time the CPU spends executing processes for people in “user space.” sy: Amount of time spent running system “kernel space” processes. ni: Amount of time spent executing processes with a manually set nice value. id: Amount of CPU idle time. wa: Amount of time the CPU spends waiting for I/O to complete. hi: Amount of time spent servicing hardware interrupts. si: Amount of time spent servicing software interrupts. st: Amount of time lost due to running virtual machines (“steal time”).
- The fourth line shows the total amount (in kibibytes) of physical memory, and how much is free, used, and buffered or cached.
- The fifth line shows the total amount (also in kibibytes) of swap memory, and how much is free, used, and available. The latter includes memory that’s expected to be recoverable from caches.
The column headings in the process list are as follows:
PID: Process ID. USER: The owner of the process. PR: Process priority. NI: The nice value of the process. VIRT: Amount of virtual memory used by the process. RES: Amount of resident memory used by the process. SHR: Amount of shared memory used by the process. S: Status of the process. (See the list below for the values this field can take). %CPU: The share of CPU time used by the process since the last update. %MEM: The share of physical memory used. TIME+: Total CPU time used by the task in hundredths of a second. COMMAND: The command name or command line (name + options).
The status of the process can be one of the following:
D: Uninterruptible sleep R: Running S: Sleeping T: Traced (stopped) Z: Zombie
If you have a multi-core CPU, press 1 to change the display and see individual statistics for each CPU.
For each CPU, top displays three numbers and the graph. From left to right, the numbers are as follows:
- The combined us and ni percentage (user space+tasks with nonstandard nice settings). - The sy percentage (kernel space). - The total (rounded to an integer value).
Changing the Numeric Units
Memory values are shown in kibibytes.
Change the display units to more readable values by presssing capital E to cycle through the units used to display memory values in these options:
kibibytes mebibytes gibibytes tebibytes pebibytes exbibytes
The unit in use is the first item on lines four and five.
Press lowercase “e” to do the same thing for the values in the process list:
kibibytes mebibytes gibibytes tebibytes pebibytes
Sorting by Columns
By default, the process list is sorted by the %CPU column.
You can change the sort column by pressing the following: P: The %CPU column. M: The %MEM column. N: The PID column. T: The TIME+ column.
TOP interactive console cmds
h |help screen z |highlight processes in red c |display absolute path of running process I |display only active tasks. n |limit the display to a certain number of lines, regardless of whether the tasks are active. t |swap the CPU displays to simple ASCII graphs that show the percentage of usage for each CPU. u |display the processes for a single user. You’ll be prompted for the name or UID. V |display a “tree” of processes that were launched or spawned by other processes k |kill a process after finding PID d |change default screen refresh interval default= 3 seconds Shift+P | to sort processes as per CPU utilization Shift+O | to Sort field via field letter Space |Force top to refresh its display right now.
Press Q to exit top
You can also install htop which is more user-friendly / interactive than original top
URL: HTOP
SSH
Here are two links to great sites that explain SSH, Public & Private Keys, SSH-AGENT etc.
# Using ssh-agent forwarding # ssh-agent forwarding
Date/time/NTP
Display systemclock, timezone and ntp status
$ timedatectl
Edit the time settings using timedatectl
$ timedatectl list-timezones $ timedatectl set-timezone <t.ex CET> $ timedatectl set-time <YYYY-MM-DD> $ timedatectl set-time <HH:MM:SS> $ timedatectl set-ntp true
AT/Cron
$ at now +15mins
at> mkdir /apa
$ atq | display at queued jobs
$ atq -c <jobnr> | displays the content of the job
$ atrm <jobnr> | delete the job
$ batch
at> mkdir /apa --> ctlr-d to save
!N.B at batch jobs are only executed when the system load average is below 0.8
URL to a Crontab generator
Crontab Generator
