qmrestore 'write zeros' question

[RobFantini]

Hello,
I'd like to understand 'write zeros' in qmrestore .

We've recently used sdelete in win kvm's and that cut down backup up size 30-50% . Same with linux kvm's using this:

dd if=/dev/zero of=zero.small.file bs=1024  count=102400

ls -lh zero.small.file

dd if=/dev/zero of=zero.file bs=1024 

ls -lh zero.file

/bin/rm -f  zero.small.file
sync ; sleep 60 ; sync
/bin/rm  -f  zero.file

My question is: should 'write zeros' turned on in qmrestore in order to make KVM's more efficient? Or is it unrelated?

I've check man pages , searched using google but could not find an answer.

thanks.

 

[dietmar]

My question is: should 'write zeros' turned on in qmrestore in order to make KVM's more efficient?

No, that would make it in-efficient.