Re: [Qemu-block] dirty bitmap restore procedure

[Michael Ablassmeier]

hi John,

On Tue, Nov 29, 2016 at 11:52:49AM -0500, John Snow wrote:
> You need to create your snapshot and add (or reset) the bitmap using
> a transaction.

What i currently not get is the difference between:

 1) create a snapshot and bitmap in an transaction OR
 2) create only a bitmap and then use the drive-backup
    with sync=full to create a full backup, like shown in the
    examples.

using the snapshot i can be sure my disk is not changed during
backup as the backing file of the snapshot gets written and
changes get commited back as i remove the snapshot, or does
drive-backup take care about this too? Does it even make
sense to create a full backup using a snapshot or should
i only use the bitmap and drive-backup feature?

As i understand based on wether i use 1) or 2) i get
the different behavior regards backing files as you
describe and must use different ways to recover.

> As an exercise, I assume?

yes, only testing here to get an understanding how it works.
 
thank you,
    - michael