Hi folks In Bcache people normally use a single SSD for both Read and Write cache. This seems to work pretty well, at least for the load we have been using here. However in other environments, specially on ZFS people tend to suggest to use dedicated SSDs for Write (ZIL) and for Read (L2ARC). Some say that performance will be much better in this way and mainly say they have different wearing levels. The issue now a days is that SSDs for Write Cache (or Writeback) don't need to have much space available (8GB normally is more than enough), just enough for the time until data is committed to the pool (or slower disks) so it is hard to find a suitable SSD to dedicate to this propose only without overprovisioning that part. On the top of that newer SSDs have changed a lot in recent times using different types of memory technologies which tend to be much durable. Given that I personally see that using a single SSD for both Write and Read cache, in any scenarios doesn't impose any significant loss to the storage, given you use new technology SSDs and that you will hardly saturate it most of the time. Does anyone agree or disagree with that ? Fernando Frediani -- 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
