Recently, we moved one of our customers from a traditional, agent based, backup solution to a virtualization aware, agentless, back-up solution. For our client, we installed Veeam Backup & Replication 6.5. If you have not tried out Veeam, you really should. Veeam simplifies managing and, more importantly, testing backups in a virtualized environment.
Veeam differentiates itself from other backup solutions by not using an agent installed on the VM. Veeam leverages Volume Shadow Copy Service (VSS) and VMware’s Snapshot technology to take the backup. Traditional backup solutions rely on software agents installed on the VM. These agents have their own VSS drivers, and can modify the native VSS.
Our client wanted both the old system and the Veeam system running until the new backup solution had been completely tested. Having two backup solutions requiring VSS processes can turn out to be problematic. After setting up Veeam for the client’s Exchange server, we ran into a problem. The Veeam backups failed, and the VSS writer returned an error. For Exchange, this failure leads to problems. If VSS does not work, Exchange will not know to clean out the old logs (assuming you don’t run circular logging. You don’t, right?), then the drive with the log files fills up. Once the drive fills up, email stops, and the phone starts ringing.
We received a specific error, yet, it didn’t identify the real culprit. The error we received:
Transient error (0x800423F3)
A search really didn’t find many results that were relevant to our situation. After digging through what we could find, I suggested we disable the old backup agent, and try the backup again. After disabling the old agent, the Veeam backup worked. It turns out the old agent blocked the native VSS from working. Unable to run both backup solutions at the same time, we opted to take one final “old school” backup and then completely cut over. Our client hoped for a little smoother transition. Though, after that leap of faith, Veeam proved to be an excellent solution.
Going forward, disabling the old backup agent might provide a quick fix for “Transient error (0x800423F3)”. Other issue might exist, but now we have a quick test to try out.
Thomas Mehling, PEI
