Disk Loop Configuration

We recently completed a a Data Domain PoC.  During the PoC we were told our disk loops were not cabled correctly.  Since then we have received conflicting information regarding how the disk loops should be cabled.  Can anyone provide a reference guide that covers this information or a recommendation (with explanation) for the following configuration:

  • DD7200 with with four port SAS controllers are in slots 7 and 8 and four disk shelves.
  • We expect that this system may expand in the future to up to eight disk shelves.
  • We want to plan ahead for scalability (even beyond 😎 and performance.

Thanks in advance.

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3 Replies
7 Thorium

Re: Disk Loop Configuration

Did you check documentation?  Not sure about 7200 (but I assume this to be generic practice), but in my case I also have drawing (sticker) on the back of DD box.

Re: Disk Loop Configuration

Unfortunately I do not have physical access to the equipment to see the back of the box.  I don't have any documentation (I think it was lost during the PoC, I've never seen any - don't ask ).  I have not tried to download documentation yet.  I had a few minutes so I thought I would post here and see if anyone had an answer.  We have time to get it right.

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3 Argentum

Re: Disk Loop Configuration

Here is the link to setup guide for DD7200. You can find cabling diagram.

<Data Domain DD7200 Installation and Setup Guide>


For performance perspective, I think it's better to connect shelves to use all four SAS controller ports.

For scalability perspective, it depends the current connectivity but I think you better use fewer loop since if you use all four loops with four shelves, you need to disconnect SAS cables when you add additional four shelves.


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