Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hello,
I have a primary/secondary node with 2 ressources.
When I watch the i/O performance i look some think like this :
When I watch the physical drive utilisation :
root at relax:~# iostat -x /dev/sda 1
Linux 2.6.32-5-amd64 (relax) 01/19/2012 _x86_64_ (16 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
0.02 0.00 1.09 0.02 0.00 98.87
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s
avgrq-sz avgqu-sz await svctm %util
sda 220.78 700.91 555.52 374.88 20794.66 21227.05
45.16 1.54 1.66 0.42 38.87
avg-cpu: %user %nice %system %iowait %steal %idle
0.04 0.00 0.17 0.00 0.00 99.79
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s
avgrq-sz avgqu-sz await svctm %util
sda 186.00 48.00 211.00 162.00 15392.00 2624.00
48.30 0.03 0.09 0.06 2.40
avg-cpu: %user %nice %system %iowait %steal %idle
0.00 0.00 0.29 0.00 0.00 99.71
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s
avgrq-sz avgqu-sz await svctm %util
sda 197.00 9.00 379.00 117.00 19472.00 1172.00
41.62 0.15 0.31 0.19 9.60
When I watch the drbd device utilisation :
root at relax:~# iostat -x /dev/drbd0 1
Linux 2.6.32-5-amd64 (relax) 01/19/2012 _x86_64_ (16 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
0.02 0.00 1.09 0.02 0.00 98.87
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s
avgrq-sz avgqu-sz await svctm %util
drbd0 0.00 0.00 775.16 1016.47 20729.96 21174.70
23.39 0.94 5.51 0.56 99.85
avg-cpu: %user %nice %system %iowait %steal %idle
0.00 0.00 0.56 0.00 0.00 99.44
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s
avgrq-sz avgqu-sz await svctm %util
drbd0 0.00 0.00 426.00 104.00 15648.00 1262.00
31.91 5.19 0.15 1.87 99.20
avg-cpu: %user %nice %system %iowait %steal %idle
0.00 0.00 0.56 0.00 0.00 99.44
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s
avgrq-sz avgqu-sz await svctm %util
drbd0 0.00 0.00 404.00 148.00 15888.00 1872.00
32.17 5.78 0.33 1.80 99.60
avg-cpu: %user %nice %system %iowait %steal %idle
0.00 0.00 0.31 0.00 0.00 99.69
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s
avgrq-sz avgqu-sz await svctm %util
drbd0 0.00 0.00 398.00 117.00 15632.00 1736.00
33.72 5.28 0.10 1.94 100.00
avg-cpu: %user %nice %system %iowait %steal %idle
0.00 0.00 0.24 0.00 0.00 99.76
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s
avgrq-sz avgqu-sz await svctm %util
drbd0 0.00 0.00 406.00 106.00 15376.00 1382.00
32.73 5.07 0.17 1.92 98.40
I don't understand why my drbd device is at 100 %util.
This is my ressource configuration : There are a raid 0 hardware with 12
sas 15k drives.
resource data {
protocol C;
startup {
wfc-timeout 0;
}
disk {
on-io-error detach;
}
syncer {
rate 20M;
verify-alg md5;
}
on surtax {
device /dev/drbd0;
disk /dev/sda;
address 10.1.42.11:7788;
meta-disk internal;
}
on relax {
device /dev/drbd0;
disk /dev/sda;
address 10.1.42.12:7788;
meta-disk internal;
}
}
What's wrong on my configuration ?
Thank's
Matthieu