Problems attaching disks in Azure under 11.1-BETA2

[Pete French]

I am trying to attach a brand new disk to an azure VM, and
what I see is the disk attachng and detaching immediately like this:

	da2 at storvsc3 bus 0 scbus5 target 0 lun 0
	da2: <Msft Virtual Disk 1.0> Fixed Direct Access SPC-2 SCSI device
	da2: 300.000MB/s transfers
	da2: Command Queueing enabled
	da2: 32768MB (67108864 512 byte sectors)
	da2 at storvsc3 bus 0 scbus5 target 0 lun 0
	da2: <Msft Virtual Disk 1.0> detached
	g_access(918): provider da2 has error
	g_access(918): provider da2 has error
	g_access(918): provider da2 has error
	g_access(918): provider da2 has error
	(da2:storvsc3:0:0:0): Periph destroyed

I have seen this before with an existing disk if I detahc and reattach
wiht a new LUN numer, but never with a brand new disk. The command I
am using to create this is below:

	az vm disk attach --vm-name az-london01 \
		--resource-group ticketswitch-london \
		--caching ReadWrite --new --size-gb 32 \
		--sku Standard_LRS \
		--disk az-london01-tank01

The only thing I could find in bug reports which is similar is this:

	https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=212914

But those patches should have gone in ages ago. Will try and find a
workaround for now, but its a bit puzzling.

-pete.