Really, using dump would be the right answer, IMHO, but Linux filesystems have rarely had a dump/restore that's up to the task. xfs and its dump/restore seem to be working out pretty well, though.

Many tars have had limitations and bugs that made it a poor choice for this sort of thing, but the gtar that's almost definitely installed under Linux has had these fixed (by using its own proprietary format), assuming it's also what you use to extract the archive. Alternately, you could use a POSIX-compliant tar like star.

Okay. Enough soapboxing.