>Why not go one step further,
>and write this information in the tapelabel.
Because planner needs it to decide how much to do before taper will
find it. It needs to be on the server in someplace like tapelist or
the curinfo database.
>> ... 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.
Then you've been lucky :-). Tapes make Murphy (of Murphy's Law) look
like the ultimate optimist.
Whenever I start ranting on this, my true point probably gets lost in the
rhetoric. I don't mind appending, but the obvious "fsf to where we left
off and start writing" approach is not safe enough. You really need to
verify where you ended up, for several reasons. One is that I don't think
you should trust tapes to do what you tell them. But just as valid is
that the tape may have been reused or whatever and doesn't look like what
you think it does. Either case calls for basic defensive programming.
So, ignoring the reasoning behind them, my two rules for tape appending
are:
1) Make sure you know where you are before you start writing.
2) Never change directions except to rewind.
The first rule shouldn't be too controversial. The second is based
on over a quarter century (it only seems much longer :-) of dealing
with these things and basic mechanics -- if you stretch something one
direction and then push it the other, it's going to bunch up.
>Come to think of it, I cannot even remeber it ahppening in the huge
>reel-to-reel tapedrive we used way back when, and that was a pretty bad
>piece of work ;)
Well, then, do I ever have a bunch of horror stories to tell you :-).
> Gerhard
John R. Jackson, Technical Software Specialist, [EMAIL PROTECTED]
