I installed flashcache version 3.1.1 and created a write-back cache. The performance is good as long as the percentage of dirty blocks is not too high. My application does heavy I/O at the beginning, and then calculates for a long time. So, flashcache has enough time to write the dirty blocks to the hdd but it writes the data at a very slow rate (2 MB/s). I tried to change that with sysctl but it didn't have any effect. How can I change the rate properly? Here is my sysctl output.$sysctl -a | grep flashdev.flashcache.sda6+sdb9.cache_all = 1dev.flashcache.sda6+sdb9.clean_on_read_miss = 0dev.flashcache.sda6+sdb9.clean_on_write_miss = 0dev.flashcache.sda6+sdb9.dirty_thresh_pct = 20dev.flashcache.sda6+sdb9.do_pid_expiry = 0dev.flashcache.sda6+sdb9.do_sync = 0dev.flashcache.sda6+sdb9.fallow_clean_speed = 100dev.flashcache.sda6+sdb9.fallow_delay = 600dev.flashcache.sda6+sdb9.fast_remove = 0dev.flashcache.sda6+sdb9.io_latency_hist = 0dev.flashcache.sda6+sdb9.lru_hot_pct = 75dev.flashcache.sda6+sdb9.lru_promote_thresh = 2dev.flashcache.sda6+sdb9.max_clean_ios_set = 40dev.flashcache.sda6+sdb9.max_clean_ios_total = 80dev.flashcache.sda6+sdb9.max_pids = 100dev.flashcache.sda6+sdb9.new_style_write_merge = 0dev.flashcache.sda6+sdb9.pid_expiry_secs = 60dev.flashcache.sda6+sdb9.reclaim_policy = 0dev.flashcache.sda6+sdb9.skip_seq_thresh_kb = 0dev.flashcache.sda6+sdb9.stop_sync = 0dev.flashcache.sda6+sdb9.zero_stats = 0PS: My system is Debian testing.
flashcache tuning
cache;sysctl