Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Thu, Jul 2, 2009 at 10:39 AM, Florian Haas<florian.haas at linbit.com> wrote: > Federico, > > out of curiosity: does this throughput drop also occur when you activate > your "TestGroup00" VG in exclusive mode? Hi Florian, I did the tests again using just LVM: # pvcreate /dev/cciss/c0d0p1 # vgcreate -cn TestGroup00 /dev/cciss/c0d0p1 # lvcreate -n TestSpeed00 -L 4G TestGroup00 # sync && dd if=/dev/zero of=/dev/TestGroup00/TestSpeed00 bs=1M count=100 oflag=direct 104857600 bytes (105 MB) copied, 1,45695 seconds, 72,0 MB/s # pvs PV VG Fmt Attr PSize PFree /dev/cciss/c0d0p1 TestGroup00 lvm2 a- 465,73G 461,73G # sync && dd if=/dev/zero of=/dev/drbd1 bs=1M count=100 oflag=direct 104857600 bytes (105 MB) copied, 1,7703 seconds, 59,2 MB/s # pvcreate /dev/drbd1 # vgcreate -cn TestGroup00 /dev/drbd1 # lvcreate -n TestSpeed00 -L 4G TestGroup00 # sync && dd if=/dev/zero of=/dev/TestGroup00/TestSpeed00 bs=1M count=100 oflag=direct 104857600 bytes (105 MB) copied, 7,3782 seconds, 14,2 MB/s # pvs PV VG Fmt Attr PSize PFree /dev/drbd1 TestGroup00 lvm2 a- 465,71G 461,71G Do you think there might be a block alignment issue? -- Federico.