What is maximum SMB2 IOCTL(FSCTL_GET_SHADOW_COPY) response size.
realrichardsharpe at gmail.com
Mon Jan 19 15:25:33 MST 2015
On Mon, Jan 19, 2015 at 2:22 PM, Hemanth Thummala
<hemanth.thummala at gmail.com> wrote:
> Thanks all for your responses.
> As Stefan(metze) and Richard pointed out, this looks like SMB2.0 limitation
> to me. In negotiate process, max trans size is limited to 64K if we are not
> supporting large MTU or multi credits.
> I have tried modifying this max trans size from 64KB to 256KB. Could see
> that it negotiating 256K with client. But there is no difference in client
> behavior when trying to send huge response(~90K). Not sure if this is SMB2.0
> client's limitation. Or we might need to port the multi-credits and large
> MTU support to really support huge response buffer size.
> If there is a clear limitation for smb2.0 protocol, we might probably need
> to truncate the response to 64K.
There is a strict 64kiB transfer size limit for 2.02 which includes
IOCTL responses, I believe.
That is why you will need to either move to 4.0 or back-port the 4.0
stuff, both of which are going to be hard, or limit your responses to
64kiB (which will mean reducing the number of snapshots you report on
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