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I am about to purchase a Dell R610 and use a H700 RAID controller. I was wanting to add 2 X SSD (480G) RAID 1, and 2 X HD (2TB) RAID 1. In reading over the manuals I saw:

SSDs require the PERC 6/i or PERC H700 integrated storage controller card and cannot be mixed with any other type of hard drive source

Is this just for the same RAID group, i.e. one cannot mix a HD within a SSD RAID group? Or is it the case we can't have to 2 separate RAID groups with the H700 RAID controller with one being SSDs and one being HDs? (This seems like the intent of that statement but it seems pretty limiting... hence the question.)

If the controller does allow different disks in the separate RAID groups, then can we turn on and off the write through / read through on the RAID controller for the different groups? I gather for the SSD's it is sometimes slower to actually have this RAID card do caching since the drives themselves can deliver data faster than the caches in the RAID? (I have read this in surfing around on the issue... It is difficult to look at tuning this before we actually get the server and drives, hence my questions now...)

Thanks, Jas

sysjas
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1 Answers1

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  • You can't mix disk types in the same RAID group.
  • However, you can mix drive types in the same server/controller.

As for caching policies, they can be configured per drive group.

ewwhite
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  • thanks! I kind of thought one should be able to do this Ie create separate raid groups and the RAID groups have different types of drives, but reading that statement it really wasn't clear. Also thanks for the answer on the caching policy. It is what I needed to know. Thanks, Jas – sysjas Dec 23 '14 at 15:03
  • "However, you can mix drive types in the same server/controller." - You mean have multiple groups? If so, how many groups can the `H700` have? Thanks! – isapir Aug 01 '17 at 18:04