Hi,

Western Digital Green drives fail early under Linux due to excessive
load/park cycling of the heads.  This should be noted in the
Installation Manual's hardware compatibility section.

For more information on the problem see the package description of the
idle3-tools package:

https://packages.debian.org/jessie/idle3-tools

the -J option of the hdparm man page:

http://manpages.debian.org/cgi-bin/man.cgi?query=hdparm&apropos=0&sektion=0&manpath=Debian+8+jessie&format=html&locale=en

and Arch Linux's drive notes:

https://wiki.archlinux.org/index.php/Advanced_Format#Special_Consideration_for_WD_Green_HDDs

Attached is a patch against head.  (It'd be nice to see this
backported to Jessie so that, at least in theory, people would not
have their drives die.)