From mboxrd@z Thu Jan 1 00:00:00 1970 From: Piergiorgio Sartor Subject: Formatting of backing device Date: Wed, 1 Feb 2012 11:10:41 +0100 Message-ID: <20120201101041.GA2779@lazy.lzy> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline Sender: linux-bcache-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-bcache-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-bcache@vger.kernel.org Hi all, first of all I would like to congratulate for this project, I think it is one of the most promising feature the Linux kernel can have. Wrote that, I've a question about the concept of formatting the backing device. As far as I understood, the first concept of bcache was to simply "register" or "attach" a cache to a backing device, that is, the backing device had not to be formatted. Lately, still if I understood it correctly, this behaviour was changed and, now, the backing device needs to be formatted. So, the question is: How about an already running device? Is it still possible to attach a cache under such situation? In general, would it be possible to attach/detach a cache to any already available device (in the future)? Or the caching/backing setup must be planned before the HW is available, so to speak? It would be useful (and cool too), to have the possibility to attach/detach the SSD cache, on the fly (at run-time) to any device it needs it. I hope the question(s) are clear, if not please let me know. Thanks a lot in advance, bye, -- piergiorgio