[mythtv-users] OT: Hybrid drives in a RAID?

[Matt Emmott]

There's a deal on slickdeals.net this morning where one can buy a 4TB
Seagate "Hybrid drive" (model ST4000DX001) for somewhere in the
neighborhood of $150 shipped. This drive has 8GB of NAND flash built in,
and from what I've read performs block-level offload of the frequently
accessed data to the flash, giving it (in theory) a performance boost
similar to SSD.

I'm planning on building a 6-disk RAID6 array in my shiny used Poweredge
once it shows up. If hybrid disks offer a speed boost at an affordable
price, it seems like a no-brainer to use them for my array. However, I
can't find any solid information on using them in a RAID5 or RAID 6 setup.
I did find this quote from HP via
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c03821563&cc=us&dlc=en&lc=en
:

>An SSHD in RAID 0, as compared to a single drive configuration, delivers
performances as >much as 70% higher.
>Because current drives are not designed for multi-drive vibrations, they
have not been tested >with RAID 5, 6, or 10, and are not recommended.

I'm going to ignore the last part about multi-drive vibrations because I
assume it's some CYA warranty fluff, and danger is my middle name. But, I
don't know what I don't know so I'm asking the smart people on this list if
they think a hybrid drive would be a benefit, or a deterrent, or something
else when running it in a RAID5 or 6 setup.

Thoughts? Thanks in advance.

Thanks,
Matt
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