On 9/27/07, John E Hein <[EMAIL PROTECTED]> wrote: > > > And maybe adding a "devno changed" check in amcheck would be nice - > > > the client has the gnutar-list files, so it would require some work in > > > the client side of amcheck. > > > > This might be an interesting addition to the GNU Tar application, when > > it's complete. I'm not sure if there's a good way to stuff it into > > the current implementation. > > I think a check is higher level than gtar. What would you do? Have > gtar grow yet another -- option, say > --check-for-incremental-devno-change? Or perhaps spew a warning if > the devno for an otherwise identical file is different? Unfortunately > it's harder to generically code a check into gtar if not using > --one-file-system (which allows you to assume devno is the same > throughout the file). If it's got a mix of devnos, you might have to > check the entire snapshot file to see if any device numbers have > changed.
Ah -- "GNU Tar Application" in this context means the Amanda application that drives GNU Tar -- part of the Application API. So GNU Tar itself wouldn't grow a new option. Rather, the application (in essence, a wrapper on steroids) would perform that check manually, using the method you suggested. > But now you have add specific knowledge of the > gtar file format to amanda, and I agree that's not so good (and this > point also applies to the sed above). This is a good point, and probably the most significant reason *not* to make this change. I'm not sure it's a showstopper, though, particularly now that the GNU Tar formats are well-documented. > I could definitely see adding a gtar option that could be used to > ignore devno changes, say --ignore-devno-change, that is used with > --listed-incremental. Then you could avoid having to do the sed > described above. And that should be a tiny code change to gtar (in > theory - </me says without looking at the source>). It's worth suggesting such an option on the Tar mailing list, to see what Sergey thinks. From my memory of the Tar code, that would indeed be a fairly trivial change. I don't remember if that particular solution was suggested before -- perhaps Gene remembers, or perhaps the tar-bugs archive can tell you? Dustin -- Storage Software Engineer http://www.zmanda.com
