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Sun Solaris UNIX comes with various commands and utilities to make a backup and recovery job:
a) tar command
b) cpio command
Task: Use tar command to backup /data and /home directory
Usually /dev/rmt/0 is tape device name.
To create a new tar file you can type:
# tar cvf home-back.tar /home /data /etc/file1
To create a new tape backup use:
# tar cvf /dev/rmt/0 /home /data /etc/file1
Task: Display the contents of a tar file/tape
Pass tvf option to tar command:
# tar tvf home-back.tar
OR
# tar tvf /dev/rmt/0
Task: Restore files from tar file / tape
To extract the tar file to the current directory type:
# tar xvf home-back.tar
# tar xvf /dev/rmt/0
Understanding tar command options:
- x : Extract tar file
- v : Verbose
- f : filename : Use to specify file name / tape device name
- t : List tar file contents
Task: Backup files with cpio command
You can also use cpio command, which copies files into and out of a cpio archive. The cpio archive may span multiple volumes. The -i, -o, and -p options select the action to be performed. For example copy all *.c files to tape device or file called prog.cpio:
# ls *.c | cpio -oVc > /dev/rmt/0
OR
# ls *.c | cpio -oVc > prog.cpio
Task: Restore file using cpio
To copy from tape back to a directory, use the command as follows:
# cpio -icvD < /dev/rmt/0
OR
# cpio -icvum < /dev/rmt/0
Task: View the contents of cpio
Use the command as follows:
# cpio -ict < /dev/rmt/0
Understanding cpio command options:
- i : (copy in) Reads an archive from the standard input and conditionally extracts the files contained in it and places them into the current directory tree.
- c : Reads or writes header information in ASCII character form for portability.
- t : Prints a table of contents of the input.
- o : (copy out) Reads a list of file path names from the standard input and copies those files to the standard output in the form of a cpio archive.
- v : Verbose
- u : Use for an unconditional copy; old files will not replace newer versions.
- m ; Retains previous file modification time.
- d: Create as many directories as needed.
Further readings:
- Read Solaris tar, tape and cpio man pages, by typing following command:
man tar
man tape
man cpio
GNU cpio is a tool for creating and extracting archives, or copying files from one place to another. It handles a number of cpio formats as well as reading and writing tar files. cpio command works just like tar, only better.
As I said earlier, cpio works like tar but it can read input from the ”find“ command. This is nifty feature. For example you can find out all *.c files and backup with cpio command.
# find / -name "*.c" | cpio -o --format=tar > c-file.backup.tar
# find / -iname "*.pl" | cpio -o -H tar > perl-files.tarYou can also specify file name using -F option:
# find / -iname "*.pl" | cpio -o -H tar -F perl-files.tarWhere,
- -o: Create archive
- -F: Archive filename to use instead of standard input or output. To use a tape drive on another machine as the archive.
- -H format: Specify file format to use.
- -i: Restore archive
You can extract archive with the following command:
# cpio -i -F perl-files.tarYou can list file inside archive i.e.
list contents of the cpio file with following command:
# cpio -it -F perl-files.tar
You can write archive of /home to tape (drive /dev/nst0), type the following command:
# find /home | cpio -o -H tar -F /dev/nst0Restore backup using following command:
# cpio -i -F /dev/nst0Backup /home dir, to remote system tape drive:
# find /home | cpio -o -H tar -F user@backup.nixcraft.in:/dev/nst0 --rsh-command=/usr/bin/ssh
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