On mercredi, 14 juin 2017 14.45:55 h CEST Philipp Storz wrote:
> Hello guys,
> 
> just take a look at this:
> >> Software Compression: 99.3 % <<
> 
> I guess your disk is totally empty, and probably you store your disk in
> something that provides thin provisioning.
> 
> During backup, you read zeros that are provided by the thin provisioning
> which is quite fast and which is compressed to only 1,8 GBytes  but during
> restore 268 GBytes of zeros are really allocated and filled with zeroes in
> your disk image.
> 
> So the speed you see is the speed that you can write data into your backend.
> 
> I expect that the iowait during restore is close to 100%, and you could as
> well do a
> 
> "dd if=/dev/zero of=/path/to/your/disk/device"
> 
>  and have the same speed.
> 
> In your case it would definitely make sense to backup the filesystem inside
> of your vm instead of the vm image.

Oh damn how can I have forget that one, good catch Philipp ;-)

Eventually, if it's sparse file, you can try to save them as they are 
See documentation about sparse.
But don't try to (un)compress sparse file, so their sparse attribute are not 
touched.

-- 

Bruno Friedmann 
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