tar VS cpio

[Sundar_7]

God ! I am bugged up with this question..

**What is the difference between tar and cpio**

Is it that cpio can copy a entire file system to a different file system ..that tar cannot do ..

Anyone with answeres please

Thanks

Sundar

[Robin Wakefield]

Hi Sundar,

How about:

tar...:
... has relatively simple syntax.
... allows you to replace archived files with different versions and append new files to the end of an archive without having to rewrite the file from the beginning.

cpio...:

... can back up files describing devices (special files), as well as data files.
... writes data in a stream format, saving space and time when creating a tape backup; cpio tends to be faster than tar and stores data more efficiently than tar.
..., unlike tar, will attempt to read a tape several times if it encounters problems.
... will skip a bad area on tape.

Rgds, Robin

[harry d brown jr · Accepted solution]

Take a look at these links:

http://www.gnu.org/manual/tar/html_node/tar_125.html

And here is another good link:

http://pcunix.com/Unixart/unix_ba.html

[melvyn burnard]

two other little points here, and that is cpio tends to be a little more confusing due to you having to include options on the recovery if theye were on th ebackupcommand line,
and tar will NOT back up device files where cpio will if you use the -x option .

The pax command will read/write both formats, by the way.
man pax

[Tim D Fulford]

tar is supposed to be vendor neutral, I don't think cpio is!

Tim

[melvyn burnard]

And if I rememeber correctly, tar is also OS independant, as it ran on RTE as well as MPE and afew other non-Unix OS's

[Christoph Plattner]

TAR also can copy device files, if the '/dev/xxxx'
are ment here. I often use
tar (GNU tar) to copy complete
root file systems.

with friendly regards

Christoph P.

[Jan Affolter]

Hi,

Seems also that tar have a limitation, couldn't read tar archive greater than 2Gb.

Maybe this was corrected, could someone give more info about this ?

Take care !

Jan

[Mike Henderson]

Another invaluable piece of information on tar that I found in the forums not too long ago is that in maintaining industry compliance, HP did not make tar handle files larger than 2Gb, as mentioned in this thread. The work-around is:
dd if=/path/input-filename bs=10240k | compress -F - | dd of=/path/output-filename bs=10240k
To uncompress, do:
dd if=/path/input-filename bs=10240k | uncompress - | dd of=/path/output-filename bs=10240k