Maintenance of linux system

BACKUP

Commands for Backup

tar
Options:
c         --  create
v         -- verbose means it will show all the error while creating creating backup.
p         -- same permission i.e. maintains the same permissions of file which is backed-up
f          -- specifies filename
t          -- table of content
x          -- extract to
z          -- zip/gzip
w        -- ask for confirmation

To create a backup

Type1: tar --create --verbose --same-permission --file /usr/backup1 /home /etc

Type2: tar -cvpf /usr/backup1 /home /etc

c-create

v-verbose  

p-maintains the same permissions of file which is created

f-to create a file
/usr  is the directory were backup is saved
backup1 is the name of backup file created
/home & /etc are the directory for which backup is created
 

To extract the content from backup
tar -xvpf /usr/backup1

To extract a specific file from backup
tar -xvpf /usr/backup1 /home/haktuts.txt

to extract haktuts.txt file from backup1 to the directory /home/haktuts.txt

To list the content of backup
tar -tvf /usr/backup1 | more
list view of files in backup useful for recovering file which name is not known

To create a zip file

zip

e.g. zip hak /usr

hak is the filename

/usr is the directory to save the zip file

To extract the zip file

unzip hak /etc

To create a gzip file

gzip filename

e.g: gzip hak

To extract a gzip file 

gzip -d filename

e.g.: gzip -d hak.gz