Also, where's the end user documentation?

On Fri, Feb 1, 2013 at 5:23 PM, Kent Overstreet [off-list ref] wrote:

On Fri, Feb 1, 2013 at 4:57 PM, Michel Lespinasse [off-list ref] wrote:

quoted

On Fri, Feb 1, 2013 at 4:44 PM, Darrick J. Wong [off-list ref] wrote:

quoted

This is a patch to migrate STEC's enhanceio driver out of their github
repository and into the staging tree.  From their README:

"EnhanceIO driver is based on EnhanceIO SSD caching software product developed
by STEC Inc. EnhanceIO was derived from Facebook's open source Flashcache
project. EnhanceIO uses SSDs as cache devices for traditional rotating hard
disk drives (referred to as source volumes throughout this document).
EnhanceIO can work with any block device, be it an entire physical disk, an
individual disk partition,  a RAIDed DAS device, a SAN volume, a device mapper
volume or a software RAID (md) device."

What's your take on the benefits of this vs bcache ?

I've been trying to review it it for cache coherency and consistency
wrt. power failures, but the complete lack of high level documentation
is making that difficult.

I saw some benchmarks the other day where on writes EIO was faster
than the raw device, which was... suspicious.