Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi, > have you tried with elevator=deadline? > what does "cat /sys/block/dm-*/queue/scheduler" show? i did a couple of days ago, but just tried it again: For the '/sys/block/dm-[0,1,2]' i do not have a scheduler-file. Only for /dev/sd[a,b] This link at heading 16.3.3 fully describes what just tried: http://www.drbd.org/users-guide/s-latency-tuning.html Here are the currently active settings: /sys/block/sdb/queue/scheduler => noop anticipatory [deadline] cfq /sys/block/sdb/queue/iosched/write_expire => 1500 /sys/block/sdb/queue/iosched/read_expire => 150 /sys/block/sdb/queue/iosched/front_merges => 0 Im sorry to report, that did not change a thing. dd with oflag=direct is still slow and without the flag the load still jumps through the roof. What surprises me the most is the delay between the load rising and the finished dd. a short timeline to make myself clear: 01:00:00 load 0.5-1 01:00:00 dd if=/dev/zero of=./test-data.dd bs=4096 count=10240 01:00:01 dd finished successfully 01:00:05 load 0.5-1 01:00:10 load 2.5-3 01:00:18 load 3.5-4 01:00:22 load 3.0-3.5 01:00:45 load 2.8 01:01:00 load 1.7 01:01:10 load 1.5 01:01:30 load 1.2 01:02:00 load 0.8 regards volker