eSATA support in RHEL55

Hi,

I am new here and a newbee in Linux in general, since I am into Linux as this OS is preferred in bioinformatics. I acquired Dell PowerEdge 610 for this purpose that runs RHEL55. The intended jobs require storage and transfer of dozens GB of data, so storage space and speed of transfer is prime. I was surprised hoverer to find that the box cannot see external drives of more than 2 TB. The only suggestion I got is to upgrade to a new kernel. Is that the only option?
For 2 TB external drives, it seems that the only option is USB 2.0, which is supported. But what about eSATA? Internal drive interfaces said are SATA compliant, so I guess the kernel supports SATA drivers, but three is no eSATA connectors. Any advice on support of add-on boards?

Thanks,