Re: free space considerations writing bhyve image to a zvol

You can test how much it will compress your linuxvm.img.

$ [/tmp] ls -l ./bla.txt
-rw-------  1 ronald  wheel  5242880 Oct 18 15:39 ./bla.txt

$ [/tmp] lz4 -c ./bla.txt | wc -c
   20604


So do "lz4 -c linuxvm.img | wc -c" and it will print about the size of the zvol you need.

NB: What keeps you from just trying to write it to the zvol and see if it works?

Regards,
Ronald,

 
Van: void <void@f-m.fm>
Datum: woensdag, 18 oktober 2023 14:58
Aan: freebsd-fs@freebsd.org
Onderwerp: free space considerations writing bhyve image to a zvol
> 
> A linux file-backed vm was created initially like this:
> 
> truncate -s 2T linuxvm.img
> 
> Within the vm, df -h reports 1.1Tb used in total.
> Externally, on the freebsd host, the linuxvm.img is 2Tb.
> 
> If i write the vm to a 1.6Tb zvol with compression set (lz4),
> would it be feasible to expect the vm to work?
> 
> I expect it might break the vm's filesystem internally,
> now, thinking about it.
> -- 
>  
> 
> 
>