On Thu, Aug 2, 2012 at 1:01 AM, Piergiorgio Sartor <piergiorgio.sartor@xxxxxxxx> wrote: .. > At the moment, I've 1TB RAID-10, of which /usr is > 24GiB (10GiB used), /home is 64GiB, and then there So this is a desktop then? > are two "work area" volumes of 250GiB. > > Some other space is spread around /var and similar, > and there is some backup space, for future use. > > Any idea on what could be "minimum" SSD size (due to > cost, of course). What is your objective? To speed up normal Desktop tasks such as booting and loading applications? I haven't kept to date with bcache, so my advice may be outdated, but... Given that you only use 10GB of usr my hunch would be that 16GB would be plenty; However, at 16GB speed is a concern, particularly as 16GB SSDs are usually sitting on the other side of a USB2 port. The maximum write speed of your raid array is going to be capped to the write speed of the SSD unless you use write-around. If price is really a concern you could try using an old 4gb usb stick to writearound cache /usr, and see it that helps somewhat. In summary, if you want the benefit of writeback caching, get a decent 2.5" internal SSD. Internal SSD are pretty much always at least 32GB, which should be plenty for normal Linux desktop use. Hope this helps, -- John C. McCabe-Dansted -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
