Hi James,
Yes, I've checked bcache, but as far as I can tell you need to manually configure and register the backing devices and attach them to the cache device, which is not really suitable to dynamic environment (like RBD devices for cloud VMs).
Benjamin
> -----Original Message-----
> From: James Harper [mailto:james at ejbdigital.com.au]
> Sent: Tuesday, July 08, 2014 10:17 AM
> To: Somhegyi Benjamin; ceph-users at lists.ceph.com
> Subject: RE: Using large SSD cache tier instead of SSD journals?
>
> Have you considered bcache? It's in the kernel since 3.10 I think.
>
> It would be interesting to see comparisons between no ssd, journal on
> ssd, and bcache with ssd (with journal on same fs as osd)
>
> James
