Does it mean that there was not enough space in the holding disk and
amanda had to wait ?

If so, why does amstatus tells me that my backup was in "no-hold"
about 95% of the time, when I backed up 8 gb and I had about 150 gb
free on the holding disk ?

I've posted a question about that a couple of days ago but got now
explanation about the no-hold.

Thanks a lot.