F20 System Wide Change: SSD cache

[DJ Delorie]

> it's not going to be shoved down your throat.

I've found this to be untrue in Fedora.

> > At the very least, this feature should be disabled if the
> > SSD is the boot/root drive.  When SSDs fail, they fail
> > completely, and it's irresponsible to cause early failure
> > on a drive that's critical for booting and OS operation.
> 
> By default, bcache runs a write-through cache -- it only
> caches clean data. If the caching SSD dies, the bcache layer
> can just forward requests to spinning drive. No data is lost.

No, I wasn't worried about the spinny disks.  I was worried about the
SSD itself, in the case where the SSD hosts both boot/root *and* a
cache for, say, a /home array.

> > Also, I think such features should be postponed
> > until/unless there's a clear and obvious way to
> > configure/disable them that doesn't involve installing
> > additional packages or editing obscure text files.
> 
> Again -- no one is forcing you to use this. It's opt-in.

Please read the /tmp-on-tmpfs thread for an example of what I'm
worried about.