storage - When to Use Nexenta or OpenFiler or GlusterFS

I am not an expert in storage solution and I ma eager to understand the big picture when choosing Storage OS like when we choose to Nexentastor or OpenFiler or GlusterFS

Those three apps are only the example since from my understanding each has its own characters that can be bound together

If anyone here can give further explanation I will be very grateful

Answer

openfiler is good if you need an iSCSI or feature-rich NAS storage solution on a single machine with direct storage. Something like Gluster is good when you have an array of machines and you need to store the data across multiple servers. This is better for write-only operations as reads can be much slower.