Issues while untaring tarball with acl

Question

I am getting an error “Unknown file type 'A', extracted as normal file” while un-taring a set of files which has acl permissions set.

I had created the tar file in Solaris with tar -cpfv Tarfilename.tar directory. If I un-tar with tar xvpf Tarfilename.tar, it works great in Solaris. I had copied the tar file to Linux and tried to untar using tar xvpf, it throws the warning “Unknown file type 'A', extracted as normal file” and created files without ACL permissions.

tar --version in Linux: tar (GNU tar) 1.15.1

Answer 1

Solaris uses NFSv4 ACLs while Linux uses POSIX ACLs. They are not directly compatible.

While Linux is (naturally) using gnu-tar, as you pointed out, I suspect that on Solaris you're using Solaris' native tar.

According to the Solaris tar(1) man page:

p

Restore the named files to their original modes, and ACLs if applicable, ignoring the present umask(1). This is the default behavior if invoked as super-user with the x function letter specified. If super-user, SETUID, and sticky information are also extracted, and files are restored with their original owners and permissions, rather than owned by root. When this function modifier is used with the c function, ACLs are created in the tarfile along with other information. Errors occur when a tarfile with ACLs is extracted by previous versions of tar.

You should use gnu-tar on Solaris if you're using the -p flag to preserve permissions and the tar will be extracted on a Linux system.

If you're using Solaris 11, install the gnu-tar package which will be located in /usr/gnu/bin/tar or /usr/gnu/bin/gtar. If you're using a release earlier than Solaris 11 you'll need to get gnu-tar from Sun FreeWare (which may be available on your Solaris Companion CD).