Restore VM: [space reduction due to 4K zero bocks 3.75%] - What does it mean exactly?

[Netizen]

Hello,

I am restoring VMs taken from a different server and at the end of the restore I am getting messages similar to the one below:
====
....
total bytes read 16106127360, sparse bytes 9157279744 (56.9%)
space reduction due to 4K zero bocks 3.75%
TASK OK
====

Can someone explain briefly what is this message and whether this a 'potential problem' or not?
I am not saying that I have any issues, at least not apparent to me.
Any advice is most welcome.

N

 

[mir]

Re: Restore VM: [space reduction due to 4K zero bocks 3.75%] - What does it mean exac

Just a guess.
1) Your other servers disks are using a 4k block size and the server you have restored to uses a 512B block size
2) Your other servers disks are using a 512B block size and the server you have restored to uses a 4k block size

 

[dietmar]

Re: Restore VM: [space reduction due to 4K zero bocks 3.75%] - What does it mean exac

total bytes read 16106127360, sparse bytes 9157279744 (56.9%)

56.9% of the image contains zeroes.

space reduction due to 4K zero bocks 3.75%

We have made some optimizations for better detection of zero regions. This just tells
that this optimization saves additional 3.75% of space.

 

[Spirog]

Re: Restore VM: [space reduction due to 4K zero bocks 3.75%] - What does it mean exac



56.9% of the image contains zeroes.



We have made some optimizations for better detection of zero regions. This just tells
that this optimization saves additional 3.75% of space.

Thank you @dietmar
That's what I thought as well. Glad to know Proxmox is doing this

Kind Regards,
Spiro