Support Case #02261750
I have just logged this new case, but in the meantime thought I might post it here in case anyone has any suggestions. Since yesterday I have been unable to backup any of my VM's running on Hyper-V. The Veeam backup server and Hyper-V host are both Windows 2012 R2 with all the latest patches up until last weekend. My backups are targeted to either of two iSCSI targets. Each target is presenting a single LUN. I am running Veeam B&R 9.5 U2.
My backups were running fine on Monday, Tuesday and Wednesday this week, but stopped working on Thursday 27th.
The full error I get is 28/07/2017 08:24:59 :: Error: Failed to call RPC function 'StartAgent': An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full. Cannot connect to socket.
This exact error is mentioned in https://www.veeam.com/kb2289
, except I do not have KB4015553 installed as the article suggests (I do have KB4015550 installed however). Anyway, the suggested fix of installing Microsoft KB4025335 on the Veeam server has not helped. Neither has the workaround of removing any unused iSCSI targets.
I removed the iSCSI targets, rebooting the Veeam server, then re-attached the targets but this has not fixed the issue.
There is a similar discussion going on at veeam-backup-replication-f2/veeam-server-100-cpu-rpc-errors-and-backup-failures-t40810.html
with talk of installing and uninstalling KB4025335 and KB4025336 (both are installed on my server). The post also seems related to Server 2016, ReFS and CPU's stuck at 100% - none of which apply to my situation. I also have the latest NIC drivers installed for my system.