Migration strategy to external data storage

[mphelpsmd]

I'm running CentOS 6.7 on my Supermicro-based server and I'm starting to run out of drive space on the internal hard drives. The two fixed internal hard drives are 2TB each and run in software RAID 1.

I put a USB 3.0 card in the machine which should allow me to utilize an external RAID system and get decent data transfer rates. I'm looking at something like the Datoptic four-drive RAID like this one: http://www.datoptic.com/ec/1u-rackount- ... esata.html.

I figured I would copy the data to the external drive and mount that new drive at the /srv mount point where that data is now. The OS would continue to reside in the internal HD's as it is now. OK, no problem.

My question here is how I can do this optimally from the start. I'm only talking about a few TB of data max that I anticipate, so I could use ext4. Should I configure it to be JBOD and use a filesystem like Btrfs? Or should I let it do hardware raid and use an ext4 or xfs filesystem? If the latter, can I use LVM to establish more flexibility for future expansion?

I'm looking to leverage people's experience with this so that I don't have future regrets over decisions I make now.

Thanks in advance,

Mike