Hi,<br><br> As a result of running this command, 'iostat -x -m 30 30'. I get the following output. sda and sdb are sata3 drives in a striped raid (0). <br><br> How do I interpret these results for a raid. Specifically,<br>
a) await to svctm ratio is close to 1 for individual drives but > 2 for dm-x. <br> b) I expected to see rMB/s closer to 300 which is the SATA3 speed with the reasonable good disks I am using. But these are at 1.xx MB/s. What does thie mean?<br>
c) What's the interpretation to monitor the raid performance? Seems like there is enough bandwidth for I/O here but when I bump up the processes just a notched, there is a long await to svctm ratio.<br><br>Thanks,<br>
Madhav.<br><br>avg-cpu: %user %nice %system %iowait %steal %idle<br> 33.62 0.00 6.90 0.02 0.00 59.45<br><br>Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s avgrq-sz avgqu-sz await svctm %util<br>
sda 10.03 0.20 20.37 0.20 1.16 0.00 115.19 0.05 2.63 2.53 5.21<br>sdb 10.07 0.00 19.97 0.13 1.15 0.00 117.67 0.05 2.65 2.56 5.14<br>dm-0 0.00 0.00 41.93 0.47 2.31 0.00 111.60 0.12 2.88 1.35 5.70<br>
dm-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00<br>dm-2 0.00 0.00 41.93 0.47 2.31 0.00 111.60 0.12 2.88 1.35 5.71<br>dm-3 0.00 0.00 41.93 0.40 2.31 0.00 111.77 0.12 2.89 1.35 5.71<br>
dm-4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00<br><br>