Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Lars Ellenberg <Lars.Ellenberg at ...> writes: > > So how can I check why drbd slows things so terrible down? Yes there is a > > bottleneck. But without drbd all seems fine, with drbd not. > > see what io scheduler is in use > (/sys/block/lower-level-device/queue/scheduler) > on servers I prefer "deadline". > you can switch to "deadline" like this: > for q in /sys/block/*/queue/scheduler ; do > echo deadline > "$q" > done > or by specifying a boot-time commandline parameter. > > if that did not help yet, > check wether increasing "max-buffers" > and/or decreasing "max-epoch-size" in drbd.conf does help. > Neither changer io scheduler from anticipatory to deadline nor lowering max-epoch-size showed any effect. max-buffers was on the highest allowed value anyway. But decreasing didn't helped also.