I'm trying to diagnose a slow file copy issue but am a bit perplexed by the "behind the scenes" flow of data and am looking for clarification.
The server in question is a Windows 2012 server and it has a dedicated iSCSI NIC on the same subnet as the iSCSI target.
We are seeing appalling file transfer speeds from one volume to another - both of which are LUNs on the same storage array behind the same iSCSI target.
Can anyone explain how the flow of data should go for a copy job initiated by the server, from one volume to the other?
Will the server essentially pull in every byte from the relevant LUN and then spit the same bytes back out to the iSCSI target?
So, for a 20gb file copy - would it essentially download and reupload all 20gb (whether all at once or bit-by bit)?
EXTENDED COPY
andWRITE USING TOKEN
.