I have a Dell PowerEdge Server with a HW RAID controller and a 12Gbs HBA SAS Storage adapter. I'm are looking to add more storage for backup/archiving purposes. I'm looking at using the MD1200 or MD1220 to support that role as opposed to a NAS (due to limited/throttled network bandwidth in our corporate office).

If I connect the MD12XX to the server will the disks show up as Just a Bunch Of Disks; allowing me to configure it as another RAID array from the server? Or does the MD12XX need to be configured with its own RAID controller in order to be accessed single logical disk?

If the answer is the former, is there a performance benefit for the MD12XX having its own RAID controller?

The purpose of this server is for computation of large data sets and software development as opposed to hosting cloud based web services or virtual machines.

2 Answers 2


DAS enclosures are attached to the server via a RAID host-bus adapter (HBA) with external SAS cables. Generally, you will have the option to purchase a compatible HBA when you configure the enclosure or you can use one of your own if you have one already (make sure it is a RAID card and not one for use with something like a tape backup drive).

I think you may be getting confused by the RAID controller option in the configuration. This is not a controller that is installed in the enclosure, but rather a compatible HBA that you install in an open slot on your server then attach to the array with the included cables.

The drives will be available to configure via the newly installed RAID controller similar to how you configure the drives attached to your internal backplane and its associated internal RAID controller. Once you provision a virtual disk, it should show up in your OS like any other direct-attached disk would.

You can think of the DAS enclosure like a large, externally attached backplane, because that's essentially what it is. An enclosure with its own RAID controller would need an alternate attachment method like Fiber Channel or iSCSI and would then no longer be considered a DAS.

  • What I am referring to is Dell's MD1200 configuration page which allows a person to select a RAID controller (Screenshot). I currently have a H730 card in the server now. The HBA SAS card is this -- SAS 12Gbps HBA External Controller. So the RAID controller for purchase would be the for installation in the PowerEdge rather than the DAS. Am I understanding you correctly?
    – Wanderer
    Feb 18, 2016 at 19:02
  • Yes, the controller in the configuration page is for installation into your PowerEdge server or another server. It does not go in the DAS.
    – learley
    Feb 19, 2016 at 2:15

The 1220s connect directly to the server's host-raid adapter - I believe the H800 is required for the 1200/1220. As far as benefit, the 1200 is slower, the 1220 is faster. If speed's your goal, 1220 - if more at-rest storage is desired, the 1200 is a good option and probably cheaper.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .