MultiTape Tar files

[Jerry LeVan]

hello netters,

There appears to be some obscurity in the tar documentation
(online). I wanted to backup my X11 source and binaries. They
are currently living on an HD80 (a single aux partion for the whole
disk). When I tried tar<~k> to get the commando help I generated
a command line:

        tar cvlbBf 16 4500 /dev/rmt/tc1 .

The resulting execution would write only about 150 files to the
tape and call for another "disk". After about 3 tapes were
quickly called for I realized that something was obviously wrong

I though perhaps there was a blocking problem so I tried:

        tar cvlbB 16 4500 - | tcb > /dev/rmt/tc1

Same problem.

The online man page for tar claims that the B option is the size
of the device in 512 byte blocks, so I am trying the following

        tar cvlBf 72000 - | tcb > /dev/rmt/tc1

This seems to be putting many more files on the tape and
the program has just asked for another tape...

Hmmm...That was quick the second tape only had 7 files with about
200 (512 byte blocks) written when tcb croaked with an I/O error.

Sigh...Is there a definitive technique for creating a multitape
tar /cpio archive (and of course restoration)?

Can anyone think of any reason that using system utilities
needs to be an experimental science?


Jerry
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| Jerry LeVan                           | Phone:(606)-622-1931              |
| Department of Computer Science        |                                   |
| Eastern Kentucky University           | Email:matlevan at eku.bitnet         |
| Richmond Ky 40475                     |                                   |
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|      "The series converges so slowly that it actually diverges."          |
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