Have not used Linux with these drives, but I do have a few Windows systems (laptops) with them.  Essentially, the SSD side is an enlarged cache and does not appear as a separate device to the OS - which makes them transparent.

Basically, the idea is to enlarge the cache on the media side of the drive's interface to improve performance.  The effect is supposed to allow a lower RPM speed drive to perform at a level comparable to a higher RPM drive.  Haven't done side by side comparison, but I think the actual performance boost is smaller than advertised from my experience.

--- A

--- Original Message ---

From: "Yasha Karant" <[log in to unmask]>
Sent: January 27, 2015 11:22 AM
To: [log in to unmask]
Subject: Hybrid disk drives

There are hybrid disk drives that have a "small" SSD flash memory along
with the regular spinning media, typically to serve as a cache for lower
latency.  Does anyone have long term experience with these units?  Most
flash memory is not designed for the long term repeated read/write/erase
cycles of a primary disk drive -- how are these holding up?  Is the
flash configuration totally transparent to the Linux file systems and
formatting operations?

Yasha Karant