There is 2 modes for creating an XOSAN storage. They are different and the choice is done forever. You can't switch from a mode to another when XOSAN is created, except by removing and re-creating it.
That's why it's very important to understand pros and cons of each type.
On "top" of there 2 types, you can also decide to spread all operations to multiple number of volumes. This is called distributed mode. It's very similar to RAID 0, which can be placed on top of a RAID 1 for example. We'll talk about it in the end of this guide.
Here is those 2 types:
In the vast majority of cases, replicated is better, because:
- it's almost ALWAYS faster
- it's easier to manage
- it's easier to grow
The only downside is that replicated will "waste" more space.
Using disperse makes sense only if:
- you have big HDDs and you want use the space at most
- you don't use database (or don't care about performances)
- you store big files and you don't need ultra fast data access