Once you have set up a glusterfs volume, you might want to expand the volume to add storage. This is an astoundingly easy task.
The first thing that you’ll want to do is to add in bricks. Bricks are similar to physical volumes a la LVM. The thing to bear in mind is that depending on what type of cluster you have (replicated / striped), you will need to add a certain number of blocks at a time.
Once you have a initialised the nodes, to add in a set of bricks, you need the following command which adds two more bricks to a cluster which keeps two replicas.
$ gluster volume add-brick testvol cserver3:/gdata cserver4:/gdata
Once you have done this, you will need to rebalance the cluster, which involves redistributing the files across all the bricks. There are two steps to this process, the “fixing” of the layout changes and the rebalancing of the data itself. You can perform both tasks together.
So, I am catching up a bit on the technical documentation. A week taken to play Skyrim combined with various other bits and pieces made this a little difficult.
On the bright side, there are a few new things that have been worked on so hopefully plenty of things to cover soon.
We manage a number of servers and all over the place and all of them require to be backed up. We also have a number of desktops all with mirrored disks also getting backed up.
I like things to be all nicely efficient and its annoying when one server / desktop runs out of space when another two (or ten) has plenty of space. We grew to dislike NFS particularly due to the single point of failure and there were few other options.
We had tried glusterfs a few years ago (think it was at version 1.3 or something) and there were various issues particularly around small files and configuration was an absolute nightmare.
With high hopes that version 3.2 was exactly what we were looking for, we set up three basic machines for testing