Veeam Backups - Forces IBM SAN to use only 1 Fibre Path ?

[Dmont]

Hi Guys,

This is my first posting, so first off, hello ! and a big apology if this is a silly query.

I'm looking into an issue our company has when Veeam kicks in for its nightly backups. Our Set-up and issue is as follows :

VMware VSphere 4.1, running 4x IBM 3650 M1 Hosts connected to 2 Brocade Fibre Switches,
SAN - IBM DS 3400 with SAS and SATA shelves, Multi-Channel Fibre NIC's with Preferred Paths configured ( A and B ),
Veeam Server - Veeam 6.1.0.181 - Physical Windows 2008 R2 with dual Fibre NIC ( Qlogic ) connected to the same 2 Brocade Fibre Switches,
The VM hosts and Virtual Servers can all access the SAN via multi-path Fibre and use the Preferred Path configured on the SAN ( thus load balancing SAN traffic ).

The issue seems to be when the Veeam Server starts it's nightlys, that server "can only access one of the Preferred Paths on the SAN". When this happens the SAN switches all traffic ( including the VMs ) to use the Path the Veeam Server has in use. We need to wait until backups are complete before Preferred Paths need re-configured on the SAN..
Now when I say the Veeam Server "can only access one of the Preferred Paths on the SAN ", it can and does have access to both Paths ( A and B ) but when the backup kicks off, it forces all traffic through one NIC channel and thus turning off Preferred Path on the SAN...

Can someone assist me please in resolving this issue, I'm not sure if the issue is down to the NIC configuration on the 2008 r2 Server or a setting in Veeam... If you need more info please let me know..

Many thanks

Dmont

[dellock6]

Have you enabled MPIO on the windows server to use multipath and thus both HBAs?
http://technet.microsoft.com/en-us/libr ... S.10).aspx

Be careful there are some reports stating in some situations Veeam proxies are faster with disabled mpio, maybe you could also test proprietary multipath software coming from HBA vendors (qlogic or emulex usually).

Luca.

[Dmont]

Hi Dellock,

You are absolutely right, we are using MPIO for multi-path.

Thank you very much for pointing me in the right direction, I'll have a read of the technet article you linked to and see what proprietry software we can get from QLogic.

Thanks again Dellock,

Dmont