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The Google hammer has failed me, so I turn to this august body for help :-)

I'm interested in doing SSD/HDD RAID1 pairs using the principle of 'write-mostly' as available in Linux's software RAID suite. This means I would be writing to both drives, but reading almost entirely from the SSD. However, i would very much like to be able to do this in hardware, using an LSI RAID Controller.

After looking through the CLI manuals and etc, I am a bit stumped. Does anyone have experience with this setup in hardware for any controller, but especially the LSI models?

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Not sure about LSI, but Adaptec has that - "Hybrid Raid". Not "mostly" - 100% reads go to the SSD, writes obviously to both ;) Getting a couple of SSD now for our main database server... – TomTom Jun 3 '13 at 20:07

It's not true RAID1, but MegaRAID CacheCade will allow you to put a SSD in front of a set of drives and have it work as a write-though cache. AFAIK, it's the closest answer to your question. You'd want to do a RAID1 of two disks with a SSD in front.

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That sometimes is inefficient (talk data warehouse).This is why Adaptec supports that AND a hybrid raid (1 regular disc paired with 1 ssd, all reads to the SSD) as the OP asked for. I can not imagine MegaRaid does not offer that ;) – TomTom Jun 3 '13 at 22:25
Well TomTom, I can definitely imagine it. :-) If you have any pointers towards resolution with LSI, I'd appreciate. Otherwise, it looks like Adaptec is in our future. – user129070 Jun 4 '13 at 18:53

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