Re: [Qemu-block] [Nbd] write_zeroes/trim on the whole disk

[Alex Bligh]

> On 23 Sep 2016, at 22:21, Wouter Verhelst <address@hidden> wrote:
> 
> On Fri, Sep 23, 2016 at 02:00:06PM -0500, Eric Blake wrote:
>> My preference would be a new flag to the existing commands, with
>> explicit documentation that 0 offset and 0 length must be used with that
>> flag, when requesting a full-device wipe.
> 
> Alternatively, what about a flag that says "if you use this flag, the
> size should be left-shifted by X bits before processing"? That allows
> you to do TRIM or WRITE_ZEROES on much larger chunks, without being
> limited to "whole disk" commands. We should probably make it an illegal
> flag for any command that actually sends data over the wire, though.

I'd prefer an approach like this. Perhaps X could be negotiated
with the block size extension (or simply be defined as the
'preferred block size'.

This could then be defined to work with all commands.

-- 
Alex Bligh