On Thu, 8 Feb 2001, Gerhard den Hollander wrote:
> * John R. Jackson <[EMAIL PROTECTED]> (Wed, Feb 07, 2001 at 09:14:26PM -0500)
>
> >>Now, am not 100% certain on how taper does write the files to tape ...
> >
> > Very quick review:
> >
> > Rewind
> >
> > Read the label and verify
> >
> > Rewind
> >
> > Write a new label and tapemark
> >
> > Write a header, image and tapemark
> >
> > Write a header, image and tapemark
> >
> > ...
> >
> > Write the trailing label, tapemark and quit (leaving the tape where it is)
>
> >>... Why not [save] the last one in tapelist, and/or amount of tape used?
> > That's the plan.
>
> Why not go one step further,
> and write this information in the tapelabel.
>
> Of course, this breaks if fsf is broken ...
>
> >>so, now you are effectively doing an 'mt fsf <last field>' to get to end
> >>of tape ...
>
> > True. The problem is that the drive may screw up. You may tell it to
> > skip 37 files and it skips 36 (or 38, or 10, or 100 ...). So you have to
>
> Is this still the case with newer tape drives ?
> I cannot remeber ever having this probelm with exabyte , mammoth or LTO
> tapes.
We've been using Legato at work for the past 3 years, on an older DLT2700
and a newer DLT7000, and I've never seen this happen, and they happily do
append to tape ...
See, the real problem that I have with this lack of ability is that it all
appears to resolve around finding that first position when the backup
starts ... once its found, its considered "safe" ... so any delay in the
backup will happen right at the beginning, while the dumpers are working
at pulling down data ...
