[ltp] Thinkpad X301 SSD upgrade

[Bjørn Mork]

Just upgraded the original SSD after starting to get nervous about the
Media_Wearout_Indicator being 0 for a very long time.  I have no idea
about the amount of data written to it, but it's a lot. So although I
did not notice any failures I did not want to wait for it to happen any
longer.

The Power_On_Hours was more than 11000 hours and most of those would be
*actively in use* hours.  After all, this SSD was more than 4 years old
and used for both work and private purposes all that time.

Now, considering that 1.8" form factor SSDs are pricey and the currently
available models are all dated, I conluded that this is a dead end.

However, many vendors have recently released mSATA SSDs with specs
comparable to their 2.5" cousins.  Although the X301 cannot use these
directly in any mini-PCIe slot (they need SATA signalling even if they
look like mini-PCIe), there are simple adapters available to convert
mSATA to 1.8" micro SATA (and of course 2.5" as well, but that is not
interesting wrt the X301).

So I decided to try the new 240GB Intel 525 SSD.  And it worked like a
charm, like expected, for half the price of a 1.8" SSD using
considerably older controller and storage technology.

A few pics: http://www.mork.no/~bjorn/thinkpad-ssd/

Some of the main advantages compared to the original SSD are
 - 10x speed (mostly limited by the X301 SATA II 3Gbps interface)
 - integrated AES-128 encryption, saving CPU (and thereby power) and
   complexity by obsoleting LUKS + LVM
 - TRIM support, enabling the firmware to keep the speed up
 - significantly lower power consumption (even if we ignore the software
   encryption mentioned above)

And of course:  The Media_Wearout_Indicator is still at 100 :)

Regarding the integrated encryption: There is not much information
available regarding the 525 series yet, but reading
http://vxlabs.com/2012/12/22/ssds-with-usable-built-in-hardware-based-full-=
disk-encryption/
I decided that using it to replace LUKS was acceptable for my use,
provided the SSD vendor understands how this should work. I.e. by using
the ATA passwords set by the BIOS to encrypt the keys stored on the SSD.
It is important to note that not all vendors do this.  Some will store
unencrypted keys or passwords in "inaccessible" areas.

Now I guess you still can read the password and/or decrypted key out of
the controller RAM if you are able to access it while it is active, but
that is difficult enough to be acceptable for me.  LUKS have the same
problem, with slightly easier accessible RAM.


Bjørn