Veeam disconnect iSCSI storage

[ilas]

Hello!
Veeam support CaseID: #02707203
I have a windows server 2008 Enterprise R2 SP1 on which I installed Exchange 2010. Attached to the server I have 2 storage (HP MSA P2000 G3 and Dell Unity 300) connected via iSCSI through different network cards with 1Gbs speed.
Each time I try to start an Exchange backup with Veeam(connected to Exchange through a different 1Gbs interface than iSCSI), this backup generates iSCSIprt errors and the volumes mapped via iSCSI to MSA P2000 and Unity are disconnected, exchange databases are dismounting and mounting again after I stop Veeam Backup.

Below are the errors(Source: iScsiPrt):

- EventID: 20 Connection to the target was lost. The initiator will attempt to retry the connection.
- Event ID: 7 The initiator could not send an iSCSI PDU. Error status is given in the dump data.
- Event ID: 34 A connection to the target was lost, but Initiator successfully reconnected to the target. Dump data contains the target name.

What I tried :
- I set the value to 0 for the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Veeam\Veeam Endpoint Backup\EnableParallelDiskProcessing
- I increase the Receive Buffers to a value larger such as 2048
- I disable Delay ACK

Code: Select all

Subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\
Entry: TcpAckFrequency
Value Type: REG_DWORD
Valid Range: 0-255
Default: 2
New Setting: 1

Code: Select all

Subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\
Entry: TcpNoDelay
Value Type: REG_DWORD
Valid Range: 0-1
Default: 0
New Setting: 1

Nothing worked!

What else could I try?

Thanks!

[jorgedlcruz]

Hello,
Thank you for the case number, have you tried our Veeam Agent for Windows? Being an Exchange, and having iSCSI connected to it. I think that our Veeam Agent for Windows, with CBT Driver, could be of very good use.

Not sure if you have some other Mailbox server where you can give this a try perhaps.

Best regards

[chris.childerhose]

I would wait on Support but might look in to what Jorge has suggested to test things out. The Agent is very good and could solve the issue.

[ilas]

Veeam support CaseID: #02707203

After trying Veeam Agent for Windows, with CBT Driver I noticed a small improvement. Error events were a bit rarer but we still have them.
I don't know what else I could try, besides everything in the support case.

Thanks!

[PetrM]

Hello,

As far as I understand, the same error stack has been obtained after manual creation of shadow copy and diskspd test. Perhaps, it would make sense to show the result of this manual test to the storage vendor support team to clarify what is the cause of these errors during read operations.

Thanks!