Acronis Storage Gateway is the HCI solution from Acronis. The solution, which is provided to partners, allows to build a cluster of storage and computing nodes that can become both the target for the Acronis CyberProtect service, that is an on-premise storage solution for backups, but also an hyper-converged solution that allows to deploy a wide range of storage and computing services, including virtual machines.

In this post we will describe how to perform a typical maintenance operation for the Backup Storage service, that is the removal of a node from the cluster. It happens, as in our case, when you want to decommission a node that you’re going to replace either because it is not working anymore or because you want to change the topology of the cluster.

In our case we needed to replace an old node that had a specific amount of storage space with a bigger node on a faster server and with more storage space.

Step 1: release node from the Backup Storage

The first step you need to perform is releasing the node from the Backup Storage service, going to Storage Services and the choosing Backup Storage.

The menu items you need to use

Once there you will see the current topology of the Backup storage, that is all the nodes that you have allocated for that specific service. In our case, you can see only two nodes because we have already removed the third one, the one we’re going to replace.

List of the nodes currently used by the backup storage service

Should you have any other node added to your cluster but not yet used, you would see another list of available nodes here, ready to included into available backup storage space.

Now this is the part where Acronis documentation is not clear enough. They explain how to remove a node from the infrastructure, i.e. out of the whole cluster, but they’re not clear how to do that if the node is allocated. That wouldn’t be difficult per se but the real question we faced was how to ensure that no data loss will happen.

It is relatively easy to understand that you can go to the Infrastructure menu, enter Nodes and attempt to remove the node. You would easily know that once you attempt to release a node

you will be presented a choice to release the node, optionally deciding not to migrate data to other nodes thereby incurring in a data loss. However, that won’t work if you don’t deallocate the node out of existing services.

So the first step is going to Storage services > Backup storage, selecting the node that you would like to start releasing and then click on Release

Step 2: releasing the node out of the cluster

Once you click on “Release” as explained above, nothing much seems to happen. Acronis Gateway will migrate active services out of the node (for example, Primary metadata or metadata and the Storage service) and it will exclude the node out of rotations so no new data will be stored on [...]