We use Veeam 6.5 and are backing up to HP D2D CIFS shares.
The backups are failing due to networking issues. It seems that we need to provide support for Jumbo frames plus increase MTU from 1500 to 9000+. Also to turn off flow control.
This has been done however we still see hung backups. This is the behaviour when the network transfer stops and the host doesnt receive the ACK from the target.
This isnt a veeam issue as we see the problem just copying and pasting files from a source dir to a target dir.
It was just a question to throw out there to see if anyone had seen issues based on HP blade infrastructure and vmware with the use of 10Gbe networks and the transfer of large files (veeam backup files).....
I've heard about similar problems with 10G SMB shares coming out of a NAS, but with the opposite cause/effect, that is reverting from jumbo frames to usual mtu at 1500 solved the problems. I would probably check for these:
- are you sure that all the stack (veeam server -> switches -> HP D2D)? has jumbo frames enabled?
- have you tried to configure a fixed mtu value? sometimes jumbo frames are configured as "UP to 9000" but than the different components needs to handshake and choose the best mtu for them all, just like link speed autonegotiate. Maybe you can try to make it fixed at 9000.
PS: jumbo frames and mtu-9000 is the same thing, basicallty any mtu value above 1500 is considered a jumbo frame
Luca.
Luca Dell'Oca Principal EMEA Cloud Architect @ Veeam Software
thanks for the reply.
Yes the network has been reconfigured however we have now found the problem.
Its Symantec Endpoint Protection Mgr (SEPM). Known issue with SMB2 and handling large file copies.
After I deinstalled SEPM, copies worked without problems....
This is worth noteing for backups to CIFS shares!.
