Re: [Qemu-devel] [Qemu-block] [Nbd] How to online resize qemu disk with nbd protocol?

2017-01-12 Thread Alex Bligh
> On 12 Jan 2017, at 18:45, Eric Blake wrote: > > On 01/12/2017 11:57 AM, Bob Chen wrote: >> There might be a time window between the NBD server's resize and the >> client's `re-read size` request. Is it safe? > > For resize larger, it seems that it would be safe for the

Re: [Qemu-devel] [Qemu-block] [Nbd] How to online resize qemu disk with nbd protocol?

2017-01-12 Thread Eric Blake
On 01/12/2017 11:57 AM, Bob Chen wrote: > There might be a time window between the NBD server's resize and the > client's `re-read size` request. Is it safe? For resize larger, it seems that it would be safe for the server to just remember the last size it has advertised to the client. As long

Re: [Qemu-devel] [Qemu-block] [Nbd] How to online resize qemu disk with nbd protocol?

2017-01-12 Thread Bob Chen
There might be a time window between the NBD server's resize and the client's `re-read size` request. Is it safe? What about an active `resize` request from the client? Considering some NBD servers might have the capability to do instant resizing, not applying to LVM or host block device, of

Re: [Qemu-devel] [Qemu-block] [Nbd] How to online resize qemu disk with nbd protocol?

2017-01-12 Thread Stefan Hajnoczi
On Thu, Jan 12, 2017 at 3:44 PM, Alex Bligh wrote: >> On 12 Jan 2017, at 14:43, Eric Blake wrote: >> That's because the NBD protocol lacks a resize command. You'd have to >> first get that proposed as an NBD extension before qemu could support it. > >