Recently some guys reported to me that copying between new server ad old ones behaves stangely – that at some point it stops at 0 bytes, for a long time and then renews.
I did some tests on my own and what found out is that not only files got stuck at some points at 0 bytes, but also seems that copy operation is being renewed (!) somehow.
I didn’t believe my own eyes – so I copied the file on more time, but this time I was watching closely the status bar – at around 32% it started once again from 0%
Was running till, let’s say, 50% and …back to 0%, sometimes it has finished, and sometimes… I was getting notification that “file is being used by another process” information.
I engaged some of my colleagues and for all of us it was like from the x-files. However copying between two servers placed on VMware was ok, but from this VMware to HyperV machine, whether it is 2012 or 2016 – magic was happening. Suprisingly it was all good when copying files to my laptop. That last piece of the puzzle completely confused me. How come copy operation behaves trangely for 2012 server, 2016 but works for Windows 10. So it must be definately something with the VMware ESXi host itself as machines on this host were communicating all right.
And then one of my colleague asked about the network card type the VMs have – it was E1000E, then he told me he remember from old days that there were some issues wth cards od that type. Next day we changed the card types, I removed the old ones, created new, started the Vms, and – guess what? It helped, no more issues with copy operations.
So if you are experiencing some disruptions when copying files between VMware machines and some placed for instance on Hyper-V – check your network card types.