Comments on: How to Create a Multi Part Tar File with Linux

By: Dan

Dan — Wed, 25 Apr 2012 07:18:17 +0000

Ok, but how about if I have tgz files… The splitting works great but how can I use cat to join the archives again ?

I tried:

cat archive.tgza* | (tar x)
tar: Archive is compressed. Use -z option
tar: Error is not recoverable: exiting now

Then i did:

cat archive.tgza* | (tar z)
tar: You must specify one of the `-Acdtrux’ options
Try `tar –help’ or `tar –usage’ for more information.

And then finally:
cat archive.tgza* | (tar xz)

worked but it started unpacking the archive… How can I simply join it back into one archive ?

Thanks !

By: Neil

Neil — Tue, 26 May 2009 21:19:18 +0000

Perhaps a better example would show the same operation used on multiple folders

# tar -cf – /var/www /var/ftp | split -b 100m – my_backup.tar

To guard against missing or damaged pieces, install “par2cmdline”, and create parity files so that you can repair missing pieces.

To create parity files with a 15% redundency:
# par2 create -r15 my_backup.tara*
To verify:
# par2 verify my_backup.taraa.par2
To repair missing pieces:
# par2 repair my_backup.taraa.par2
To combine the pieces and extract:
# cat my_backup.tara? | (tar x)

By: Don Birdsall

Don Birdsall — Tue, 26 May 2009 12:50:01 +0000

Perhaps I am missing something. For a single large file why not simply use the split command by itself? Executing a single command might be faster than executing both tar and split.

split –bytes=1024b sdbackup.db db_backup_
cat db_backup_* > joined_file.db