Very Computer

The idea is to minimise the time the filesystem has to be unmounted thanks
to the quicker transfer time to disk, and no need for human interaction
to mount the tape. The temporary file will then be "dd"d to tape later,
(during the day). (There is a risk if you lose the disk before you
have time to copy, but at least it's only 1 days worth, and you may still
have one usable disk copy).

Well, I first tested,for simplicity, using backup by name, and it worked
perfectly, i.e. I did something like:
find . | backup -i -f- > my.temporary.file1

then

dd if=my.temporary.file1 of=/dev/rmt0

I could dd the tape back to another file, say my.temporary.file2
then restore from that with:
restore -f- < my.temporary.file2

HOWEVER, when I tried backing up by inode (incremental, not full)
, although the backup appeared
to work fine, the reverse process (as above +/-) failed, saying the
input from device - was not in backup format. The same error occurred
if I tried to restore directly from the file I'd just created, not even
going to tape and back via dd.

The good news was that I COULD restore directly from the tape (created
by the dd from my.temproary.file).
(piping a dd of the temp. file into restore didn't work either).

Does this sound like a bug (this is 3.1.5), or am I just trying to
do something impossible?

Quote:Ellwood) writes:
> I could dd the tape back to another file, say my.temporary.file2
> then restore from that with:
> restore -f- < my.temporary.file2

> HOWEVER, when I tried backing up by inode (incremental, not full)
> , although the backup appeared
> to work fine, the reverse process (as above +/-) failed, saying the
> input from device - was not in backup format. The same error occurred
> if I tried to restore directly from the file I'd just created, not even
> going to tape and back via dd.

> The good news was that I COULD restore directly from the tape (created
> by the dd from my.temproary.file).
> (piping a dd of the temp. file into restore didn't work either).

> Does this sound like a bug (this is 3.1.5), or am I just trying to
> do something impossible?

-B    Specifies that data being restored is from standard input.
      Normally, the restore command examines the actual backup medium
      to  determine  the  backup  format.   When piping the data to the
      restore command, this examination cannot occur.  The -B flag in-
      dicates that standard  input  is  in  the AIX Version 3 backup by
      i-node number.

Megan Stewart