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On 03/29/2016 10:17 AM, Kaustubh Kelkar wrote:
> Every time I tried to download the image on the compute, I get a new
> hash value (albeit, a wrong one).

On the compute node, what is the type of NIC and its driver and such?

lscpi -v | grep -A 1 Ethernet

ethtool -i <interfacename>

And are any of the stateless offloads enabled?

ethtool -k <interfacename>

Those would include checksum offload, and things built on top of it like 
TSO, GSO, LRO and/or GRO.

If you find that checksum offload is enabled, and you disable it, does 
the corrupt image download problem go away?  If so, you have a problem 
with your NIC and/or its driver getting the offloads wrong and/or 
corrupting the traffic in a place outside the protection of the 
offloaded checksuming.  One of the central assumptions with the likes of 
checksum offload in a NIC is that anything "above" the checksum offload 
in the NIC has some sort of data protection - at least parity, if not 
ECC.  This includes components in the NIC itself, the I/O bus etc etc.

If disabling checksum offload on the compute node doesn't resolve the 
matter, you might consider the same on the controller.

rick jones

(disabling checksum offload will likely also disable the offloads which 
depend upon it.)