Farkas Levente wrote: > > Paul Clements wrote: > > Per Andreas Buer wrote: > > > >>Andrew Rechenberg <arechenberg@shermfin.com> writes: > >> > >> > >>>Check /proc/sys/dev/raid/speed_limit_[min|max]. If they are set too low > >>>then your re-mirror will behave as such. To change just echo a new > >>>value: > >>> > >>>echo 30000 > /proc/sys/dev/raid/speed_limit_min > >>>echo 50000 > /proc/sys/dev/raid/speed_limit_max > >>> > >> > >>I did so - and now: > >> > >>md6 : active raid1 md16[2] sdd6[0] > >> 117185984 blocks [2/1] [U_] > >> [>....................] recovery = 0.1% (229120/117185984) > >>finish=59.5min speed=32731K/sec > > > > > > That's probably because you just lowered the values. The maximum is > > normally 100000. To check what the default values are, reboot and do: > > > > cat /proc/sys/dev/raid/speed_limit_* > > > > Then echo a _larger_ number into those files. > > > > There is no absolute maximum value (except maybe 2^32), so don't be > > afraid to raise the values to 10 or 100 times what they were. That > > should ensure that your resync speed is close to its theoretical > > maximum. > > can someone tell me what these numbers means? I think I posted something a week or two ago that explained what these are... > of course my goal (as everyones) to achieve the maximum possible > performance. Well, this is a trade-off, that's precisely why these values are tunables. These tunables govern the _resync_ speed of a raid1/5 array. They do not control the regular I/O throughput. So what you generally want to do is to set these values as high as possible without there being an impact on normal I/O (or for that matter, system responsiveness on the whole) during a resync. > can I do any harm if I set these numbers to high? Yes, the system might become sluggish or your regular I/O throughput to the device might become very slow during resyncs if these values are too high. -- Paul - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
