Backup fails at 0-1% using VCB

[tim5700]

I just installed VCB on my vCenter server.

I have my production Virtual Infrastructure running on my Compellent SAN. I have an EMC SAN mapped to my vcenter/veeam/vcb server as a disk for the purpose of backing up my VMs. When I try to run a backup with VCB in SAN mode the job fails almost immediately with the following:

Completing current object backup process VCB
error: No path to device LVID:498ce4
e7-1ecf7b30
-9186-00151
73eceb7/498
ce4e7-fd037
014-2433-00
15173eceb7/
1 found. Error: Failed to open the disk: Cannot access a SAN/iSCSI LUN backing this virtual disk. (Hint: If you are using vcbMounter you can use the option "-m ndb" to switch to network based disk access if this is what you want.) If you were attempting file-level access, stop the vmount Service by typing "net stop vmount2" on a command prompt to force vmount to re-scan for SAN LUNs and re-try the command. An error occurred, cleaning up...

[Gostev]

This is VCB error, unrelated to Veeam Backup. VCB says cannot access your storage. How did you "map" your device? Are you using hardware HBA, or software iSCSI initiator? You can try opening support cases with your SAN vendor and VMware to help you make VCB able to access the storage. As soon as VCB is able to do it (VMware support will check this by running VCB command from command line), Veeam Backup will start functioning normally.

[tim5700]

OK, silly me. I thought that the LUNs had been mapped, but they had not. I presented the LUNs up to the Veeam server, and they can be seen now. However, now the backup runs for about 24 minutes (give or take a few seconds) and fails with the same error.

Not a Veeam issue but wanted to let everyone know the status.

[Gostev]

I remember one other customer experiencing similar issue before - backups were failing intermittently in SAN mode with this error at different percentage, sometimes even completing successfully, but they always worked in the NBD mode. I believe he ended up engaging storage device vendor, while also getting replacement HBA for his VCB server. He never updated us with the resolution though, so I don't know what helped him to resolve this issue.