On Sunday 07 February 2016 22:14:08 Thomas Fjellstrom wrote: > I'm wondering what the "best" route for me to go is. There's a few options > that I know of, like flashcache, dm-cache, and bcache. The question is which > of those is better suited to my use case? bcache cons: - no maintainer, bugs living years - partition have to be formatted as bcache lvmcache cons: - in case of failure of caching device, whole cache volume stops working (data is not lost though). - cumbersome way of removing cache from LV when caching device is not accessible/failed. lvmcache pros: - One can turn on/off caching for active/mounted LV. We moved from bcache to lvmcache (knowing it's limitations) using write- through mode and for more-reads-than-writes DB access patterns [1]. [1]: Examble postgresql load (sdc is caching SSD, over sda/b RAID10). Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sda 0.00 33.93 0.07 179.13 0.00 3.38 38.59 6.23 34.75 23.50 34.76 2.63 47.07 sdb 0.00 35.97 0.03 177.17 0.00 3.38 39.04 9.57 53.99 337.00 53.94 2.97 52.66 sdc 8.03 2.63 631.07 201.13 6.04 3.35 23.10 0.19 0.23 0.19 0.35 0.15 12.34 Regards, -- Mateusz Korniak "(...) mam brata - poważny, domator, liczykrupa, hipokryta, pobożniś, krótko mówiąc - podpora społeczeństwa." Nikos Kazantzakis - "Grek Zorba" -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
