Hi,

it happened again today: I had some images to flush to tape, which
should have nicely filled up one 200GB tape.  But, tapes being a little
difficult at times, I had an EOF at a few GB from the end of the last
DLE to flush, and so amflush used a second tape, with only 20GB on it.

That's why I wanted to propose a new option `minimum_tapefill' for
amanda, which would tell the planner to only start flushing to (a new)
tape if more than a given percentage of tape space are estimated to be
used.  In combination with `autoflush', you could ensure that all of
your tapes are used to a certain percentage at least.

For my setup, I would use something like `minimum_tapefill 50', so that
dumps of less than 100GB get left on the holding disk and flushed on the
next run.  The often-recommended approach when a single tape is much
bigger than a complete day's data, to not put a tape in on Mon-Thu, and
have everything flushed to disk on Fridays, could be implemented with
something like `minimum_tapefill 90' and perhaps a second option,
`maximum_holding 5 days'.

So recap, two new options:
        minimum_tapefill (percentage of projected tape usage below which a tape
is not used)
        maximum_holding (number of days that a backup can be left on holding
disk due to above)

This functionality would obviously depend on sufficient holding disk
space available.

Do people believe these options would be useful?  Does anybody have
better ideas how to achieve the same effect?  Does anybody have ideas of
where best to implement these options?

Alex

-- 
Alexander Jolk         /         BUF Compagnie
tel +33-1 42 68 18 28 /  fax +33-1 42 68 18 29