A backup is a term that probably found its existence at the same moment computers got around.
The technologies around backups have evolved many times. Features such as deduplication, compression and automated backup verifications are becoming part of the standard feature set in backup software.
One of the latest trends I’ve seen, is using cloud-based storage, which will be my focus in this article.
Running Microsoft Exchange in a virtualized environment provides a lot of extra flexibility and even increased availability when running in a HA configuration. This short article is dedicated to some extra tuning that might be necessary in your environment.
The environment I’m talking about is consisting of 2 virtual Exchange 2013 servers, running on VMware vSphere 5.5. Storage is provided by an iSCSI-based array. Compute by HP Gen6 Intel-blades.
Ever since these servers are running, a failover is triggered by the Microsoft Cluster Service, failing all the active mailbox databases over to the second Exchange server. It seems that a snapshot creation task is triggering this failover. As we are using Veeam for backups, we contacted them to ask if there are any workaround for this issue.
Veeam released this following KB article, telling you how to decrease the cluster sensitivity and prevent the failovers to happen. In our case, these settings sadly didn’t solve our issues.
What seems to be the problem, are dropped network packets from within the Guest OS. Following this KB article by VMware, it seems there are some issues with the VMXNET3 NIC on systems that have high traffic bursts (like Exchange).
For now, these settings seem to solve our issue and no failovers are happening again, but if it arises again, I will definitely update this article.
Hopefully both possible solutions by Veeam and VMware can help you in case you are running into the same issue.
First of all I would like to wish everyone a happy New Year! This post is dedicated to my personal highlights of 2014 and give you a brief insight about the things that have been keeping me busy and how my blog is doing at the moment.