Posts tagged "cluster"

Kubernetes The connection to the server :6443 was refused – did you specify the right host or port?

In the following upcoming posts ill post some issues and resolutions in my journey installing a kubernetes cluster.

Kubernetes cluster is offline after rebooting the master.
When running: kubectl cluster-info , you get a message like above.

Mostly this is because you did not disabled the SWAP partition.
Kubernetes / docker is not designed to SWAP, it’s for high performance computing and all the deployments should be pinned with CPU/Memory limits.
When it reach a limit it should spin off a new node.

So disable SWAP so fast as you can with the following commands:
(not a linux expert, but working fine for the ubuntu distro I use).

Turn off swap ubuntu immediately:

Disable swap ubuntu forever:

Disable swap raspbian:

Exchange backup VEEAM

Veeam Backup and Replication gives the possibility to create a consistent backup from your Exchange farm. This can be a standalone Exchange system or an Exchange DAG cluster. It makes use of the Microsoft Exchange VSS writers inside the VM. The Veeam server creates a RPC connection to the Exchange servers, and place some backup scripts on the /ADMIN$ share. When the backup starts Veeam starts this script which talks to the Microsoft VSS Writers to create a consistent backup.

Enable application aware processing

To create an application aware backup in Veeam you must enable the “Application aware processing” option in the Veeam job properties. Then go to applications for application specific settings. In this tab you can configure VSS, Log and error settings. Configure settings which are suitable for your systems.

User rights Veeam Exchange backup

Select credentials which have full rights (read / write) to all files in the folder with the database.
For direct restore to your exchange farm the user must also have full access to the Mailbox. This user permissions can be set with the following command:

When you have a service account for restoring to all mailboxes you can use Exchange impersonation. This can be set with the following command:


Back-up Exchange DAG Cluster

When you create a backup of an Exchange DAG Cluster node, default all active and passive nodes are available for restore. So theoretically you only have one backup of 1 exchange node.

Tips for creating backup of your Exchange DAG Cluster:

  • Backup both of your exchange servers in one backup job, this gives you better dedup results.
  • Don’t backup your exchange nodes in separate jobs at the same time, this can cause a failover.
  • Veeam backup can cause load on your exchange server, the best situation is to create a new exchange cluster node server with only passive mailboxes.
  • When your exchange servers failover during a backup you can increase the failover time of your exchange cluster nodes. Commands for changing the cluster parameters: