Re: large file support

[Paul Eggert]

"Craig Rasmussen" <address@hidden> writes:

> The tar header fields impose size and time restrictions on fields in
> them - specifically to 12 octal digits.

Actually, the portable format is 11 octal digits, so it maxes out at
2**33 - 1 bytes.

> So if I had a file that was 2^39 bits (~550 gb) long then I couldn't
> have tar archive all its data.

For files containing 2**33 bytes or more, GNU tar uses an extension
that supports files up to 2**95 - 1 bytes.  This should be enough for
a while.  Unfortunately it is not necessarily portable to other tar
implementations.

POSIX 1003.1-2001 specifies a different way of specifying large sizes,
which postdates tar's method; nobody has had the time to implement
that with GNU tar yet, though.