Re: [Qemu-block] null-co undefined read behavior

[Fam Zheng]

On Tue, 06/13 10:47, Kevin Wolf wrote:
> Am 13.06.2017 um 10:43 hat Fam Zheng geschrieben:
> > On Tue, 06/13 09:52, Kevin Wolf wrote:
> > > (6) Make read-zeroes=on the default. Gives people worse performance if
> > > they expect that null-co:// without any options is the fastest thing
> > > possible, but it has defined behaviour by default which seems good.
> > 
> > Not that it really matters, but null-co:// is then a poor taste of name 
> > because
> > we actually gives a zero-co:// (the difference is similar to /dev/zero 
> > versus
> > null_blk in Linux).
> 
> Well, /dev/null is character device rather than a block device and you
> can't read from it at all, so the analogy doesn't quite work anyway.

Yeah, /dev/null doesn't produce any data, what I mean is null_blk:

$ sudo modprobe null_blk && ls /dev/nullb*
/dev/nullb0  /dev/nullb1

Fam