I have a large array sitting in my server containing a bit of data that is used ofter and a lot of data that is used rarely. My goal is to make the platters spin up as rarely as possible while bcache handles most of the requests to the array. I have set the disks spin-down time to 15 minutes so that during high-activity periods they don't cycle power states too much. I have set bcache parameters such: cache_mode - writeback readahead - 0 sequential_cutoff - 0 writeback_delay - 3600 (one hour) writeback_percent - 40 (won't go higher) I was hoping that this would make bcache cache everything leaving the array practically untouched for an hour. However, stats_hour/bypassed still shows megabytes of bypassed data and a cache_hit ratio of ~50% even when I'm working ONLY with the frequently accessed data portion (some 20% of total cache capacity). Also tiny writes are being made to the array despite writeback_delay not expiring. What other parameter am I forgetting to achieve what I want? Thanks, Jure -- 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
