Archiving & Tuning Flashcards
Archive folder /etc using tar and gz
tar cfz etc.tar.gz /etc
Archive folder /etc using tar and bz2
tar cfj etc.tar.bz2 /etc
Archive folder /etc using tar and xz
tar cfJ etc.tar.xz /etc
List the content of a tar file
tar tf etc.tar (t for test)
Extract tar file to a specified target directory
tar xf etc.tar -C etc-backup
What recommended ways to copy files to remote servers rsync or scp?
rsync or sftp
scp is insecure
You are in sftp. What commands are used to navigate local file system?
lpwd, lcd, lls, lmkdir
In sftpt download a directory and its full content
get -r dir
Copy dirA to serverA
rsync -av dirA servera:
Diff between:
rsync -a dirA dirB
rsync -a dirA/ dirB
First copies the folder dirA. Second copies the content of dirA
What is the name of the perf tuning daemon?
tuned
What command do you use to interface with the perf tuning daemon
tuned-adm
Install perf tuning daemon
dnf install tuned
Determine currently active tuning profile
tuned-adm active
Show all perf tuning profile
tuned-adm list
What are some tuning profiles
aws
virtual-guest
virtual-host
balanced
powersave
desktop
Activate profile balanced
tuned-adm profile balanced
Where are perf tuning profiles stored?
/usr/lib/tuned
Create a custom tuning profile
cp /usr/lib/tuned/balanced/tuned.conf /etc/tuned/custom/tuned.conf
tuned-adm profile custom
What are the sections of a tuning profile
main, sysctl
What are some fields of a tuning profile
summary
include (to inclue another profile)
Check if the perf daemon is installled
dnf list tuned
Copy file from sftp server in one single command
sftp remoteuser@remotehost:/home/remoteuser/remotefile
rsync dry run option
-n
rsync option to preserve hard links
-H
rsync option to preserve selinux context
-X
rsync option to preserve ACL
-A
When running rsync what do you do to preserve ownerships
You must be the root user on the destination system to preserve file ownership.
Static tuning
the tuned daemon applies settings when a service starts or when the profile is selected. never based on realtime activities.
dynamic tuning
tuned daemon monitors system activity and adjusts settings according to runtime behavior changes
monitor and tuning plug-ins
monitor and adjust parameter settings
Default monitor plugins
disk, net, load
Default tuning plugins
disk, net, cpu
dynamic tuning default state
disabled
How do you disable/enable dynamic tuning
set dynamic_tuning to 1 in /etc/tuned/tuned-main.conf
Show info about a tuning profie
tuned-adm profile_info balanced
Determine the most suitable profile for the system at this exact time
tuned-adm recommend
Check the value of vm.dirty_ratio
sysctl vm.dirty_ratio
