Am 12.04.2019 um 09:44 hat Richard W.M. Jones geschrieben:
> So I had a think about this.
>
> Isn't this easier/better solved by lifting the 32 bit restriction on
> the size of certain non-data requests (ie. NBD_CMD_BLOCK_STATUS,
> NBD_CMD_TRIM, NBD_CMD_WRITE_ZEROES). The client can then query th
So I had a think about this.
Isn't this easier/better solved by lifting the 32 bit restriction on
the size of certain non-data requests (ie. NBD_CMD_BLOCK_STATUS,
NBD_CMD_TRIM, NBD_CMD_WRITE_ZEROES). The client can then query the
disk efficiently to see if it starts as zeroes, and can decide on t
Proposal looks good to me in principle.
On Fri, Mar 22, 2019 at 10:06:29PM +, Richard W.M. Jones wrote:
> However the original proposal you put here seems reasonable. I have
> only one comment about it: Should the new error (ENOTSUP) be submitted
> as a separate patch to the spec?
I don't se
On Fri, Mar 22, 2019 at 12:17:59PM -0500, Eric Blake wrote:
> On 3/22/19 11:42 AM, Eric Blake wrote:
>
> >
> > Hence, it is desirable to have a way for clients to specify that a
> > particular write zero request is being attempted for a fast wipe, and
> > get an immediate failure if the zero requ
On 3/22/19 2:42 PM, Nir Soffer wrote:
>> Add a protocol flag and corresponding transmission advertisement flag
>> to make it easier for clients to inform the server of their intent. If
>> the server advertises NBD_FLAG_SEND_FAST_ZERO, then it promises two
>> things: to perform a fallback to write
On Fri, Mar 22, 2019 at 6:43 PM Eric Blake wrote:
> While it may be counterintuitive at first, the introduction of
> NBD_CMD_WRITE_ZEROES and NBD_CMD_BLOCK_STATUS has caused a performance
> regression in qemu [1], when copying a sparse file. When the
> destination file must contain the same conte
On 3/22/19 11:42 AM, Eric Blake wrote:
>
> Hence, it is desirable to have a way for clients to specify that a
> particular write zero request is being attempted for a fast wipe, and
> get an immediate failure if the zero request would otherwise take the
> same time as a write. Conversely, if the
While it may be counterintuitive at first, the introduction of
NBD_CMD_WRITE_ZEROES and NBD_CMD_BLOCK_STATUS has caused a performance
regression in qemu [1], when copying a sparse file. When the
destination file must contain the same contents as the source, but it
is not known in advance whether th
