On Saturday November 26, djani22@xxxxxxxxxxxxx wrote: > Hello list, > > I have searching the bottleneck of my system, and found something what i > cant cleanly understand. > > I have use NBD with 4 disk nodes. (raidtab is the bottom of mail) > > The cat /dev/nb# >/dev/null makes ~ 350 Mbit/s on each nodes. > The cat /dev/nb0 + nb1 + nb2 + nb3 in one time parallel makes ~ 780-800 > Mbit/s. - i think this is my network bottleneck. > > But the cat /dev/md31 >/dev/null (RAID0, the sum of 4 nodes) only makes > ~450-490 Mbit/s, and i dont know why.... > > Somebody have an idea? :-) Try increasing the read-ahead setting on /dev/md31 using 'blockdev'. network block devices are likely to have latency issues and would benefit from large read-ahead. NeilBrown - 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
