Can you build your own Drobo?

[iwod]

Or there are no software available that does it ?

 

[GregN]

Take a look at this thread, it points to two posts for the DIYer.

The core to Drobo is the ZFS filesystem, which is available in ( and was developed for ) OpenSolaris.

It appears that Oracle has killed OpenSolaris, but there are two popular distros based on it, Nexenta and OpenIndiana. Nexenta has a ZFS NAS variation call NexentaStor, which has a free community version which is limited to 18TB and an Enterprise pay for version, which contains premium features like deduplication.

Additionally, several folks have been successful (see articles) getting ZFS up and running under FreeBSD and its storage variant FreeNAS.

Hope that helps