After digging my old email archives I think those blog posts were made by Steve Todd.
This one contains DG era history. Plenty of other posts worth reading over there for those interested.
Reason I had these on my emails is because EMC guys themselves claimed it's based on Linux. :) I might as well paste relevant parts of that email here. Links are all dead now as that was 4+ years ago. CX4, which was last in CX series before being replaced with VNX was based on 64-bit Windows XP Embedded. Genuine Windows license stickers on SPs say Windows Storage Server, but that's just marketing.
EMCRemote release notes:
- EMCRemote v4.02 is required for the CX700, CX500 and the CX300 Arrays. These arrays have a base O/S kernel that are based on Window’s embedded XP.
- EMCRemote v4.02 is backwards compatible with the CX600, CX400, CX200 and FC4700, whose base O/S kernels are based on Window’s embedded NT.
Microsoft KB:
Note: EMC CLARiiON Arrays run Embedded Windows in a locked down state that is optimized as an embedded device for block level data storage functionality. EMC does not recommend or support joining the CLARiiON SPs to a Windows domain.
Blog comments:
Dale: Dear sir, is it true that the Clariion runs Windows XP embedded?
Steve Todd: Yes it is true that today's CLARiiON is running a version of Windows XP embedded. CLARiiON made the transition to a Windows-based implementation in the late 1990s.
Dale: Kind thanks, gent. So does this imply that FLARE runs as a Win32 application?
Steve Todd: FLARE currently runs as a driver in the kernel.
Steve Todd. EMC Distinguished Engineer Steve Todd is in his third decade of storage software development, and has generated over 140 patents and patents pending during that time. He writes about his experiences building software products for the storage and information industry.
Q: Does FLARE still use a Windows-based kernel?
A: FLARE uses an embedded Windows XP kernel for system call and scheduler services. All of the rest of the functionality, including all I/O ports, and intellectual property in FLARE is and has been developed by EMC.