This seems to have fixed that, thanks. I keep forgetting there's two places I have to check for configuration. LP, Jure On Fri, Dec 30, 2016 at 9:58 AM, Killian De Volder <killian.de.volder@xxxxxxxxxxx> wrote: > Also check congested_write_threshold_us, if the SSD is "congested" it bypasses it to speedup writes. > > Killian De Volder > > > On 30-12-16 09:38, Jure Erznožnik wrote: >> 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 >> > -- > 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 -- 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
