For transferring one website from one server to another, I had to take the backup. usually this is not a big issue, but this time this machine was 64 bit Spark machine and the new server was a 32 bit GNU machine. While uncompressing, I got the following error:
root@server # tar -xvf file.tar.gz
tar: This does not look like a tar archive
tar: Skipping to next header
tar: Archive contains obsolescent base-64 headers
tar: Error exit delayed from previous errors
This error happens when you create the tar-ball on 64 bit Spark machine and then trying to untar on a 32 bit GNU machine, if this is the case then solution is following, you first need to first
gzip -d file.tar.gz
#and then do
tar -xf file.tar
And it will extract without errors.
Hope that helps. Cheers!