Dears,

 

I created VM and created disk of 1TB in size, but when I check .img file, I see that it is small and it is enlarged as needed. I believe that for spped purposes it is better to assign full space to .img file since beginning.

 

Am I right?

 

And if so, how I can force unraid to create .img with full size since beginning?

 

Many thanks

 

V

If you want to dedicate the full drive to the VM you should pass the whole drive instead of making a vdisk. 

 

 

I see, so for .img file it is not possible, right?

If you create the image file manually and make it qcow2 you can apparently have it preallocated:

https://serverfault.com/questions/428868/does-kvm-raw-images-support-preallocation

 

Believe that'll simply write to the whole image so it'll take hours, and you could do the same yourself in your existing vm by just writing into a temp file until the disk is full.

 

Doubt you'll see any performance improvement from doing either of them though.

Hi, I am not sure I am given option to create is as qcow2?

You can select qcow2 in the VM template editor, yes.

But what I meant was that instead of having the image automatically created by unraid you'd need to previously manually create it from the command line to be able to supply those arguments.

I think the op is meaning, like when you download a game, steam reserves the entire 100G of space for the game download right off, as should creating a vdisk.... and yes, it is possible for qemu to do this without taking forever writing a huge file... virt-manger does this by default. this behavior helps prevent mistakes, later on when creating multiple vms, or multiple disk images, and then you forget how much space you really have left on the physical device.   In unraids annoying behavior, I am usually left to fill each disk image up with a temp file myself, usually a bunch of movies from my plex server