I just tried to use LVM for striping the RAID1 triplets together (instead of MD). Using the following three commands to create the logical volume, I get 550 MB/s sequential read speed, which is quite faster than before, but is still 10% slower than what plain MD RAID0 stripe can do with the same disks (612 MB/s).
pvcreate /dev/md{0,5,1,6,2,7,3,8,4,9} vgcreate vg0 /dev/md{0,5,1,6,2,7,3,8,4,9} lvcreate -i 10 -I 1024 -l 102390 vg0 test4:~# dd of=/dev/null bs=8K count=2500000 if=/dev/vg0/lvol0 2500000+0 records in 2500000+0 records out 20480000000 bytes (20 GB) copied, 37.2381 s, 550 MB/s I would still like to know why LVM on top of RAID0 performs so poorly in our case. -- Arcady Genkin -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/aanlktilcdxiuexhnmb7jf9cxz9k_2tkvi_2qsjtld...@mail.gmail.com