[CentOS] Re: Native Command Queueing

Thu Jul 24 23:21:38 UTC 2008
Matt <lm7812 at gmail.com>

>>I was monitoring it with SAR and there was very high level of IOWait, meaning the drive was having a hard time.

How bad does the below look?  Dual core AM2 5600+ with 4G DDR2 and
single SATA2 drive.

Matt

10:10:01 AM       all     20.54      0.00      4.09     15.85     59.52
10:20:01 AM       all     19.96      0.00      4.17     16.81     59.06
10:30:01 AM       all     15.94      0.00      2.48     14.78     66.80
10:40:01 AM       all     14.15      0.00      3.62     13.13     69.11
10:50:01 AM       all     13.77      0.00      3.53     13.52     69.18
11:00:02 AM       all     13.71      0.00      2.24     12.33     71.73
11:10:01 AM       all     14.42      0.00      3.51     13.19     68.88
11:20:01 AM       all     12.32      0.00      3.37     11.74     72.57
11:30:01 AM       all     13.93      0.00      2.54     16.23     67.30
11:40:01 AM       all     14.59      0.00      3.68     11.27     70.46
11:50:01 AM       all     12.74      0.00      3.27     11.18     72.81
12:00:01 PM       all     10.75      0.00      1.71      9.68     77.86
12:10:01 PM       all     13.32      0.00      3.26     12.21     71.21
12:20:01 PM       all     11.91      0.00      3.86     12.84     71.40
12:30:01 PM       all     13.89      0.00      2.33     11.74     72.04
12:40:01 PM       all     10.78      0.00      3.13     10.23     75.86
12:50:01 PM       all     10.78      0.00      3.07      9.47     76.68
01:00:01 PM       all      9.44      0.00      1.72     10.24     78.60
01:10:01 PM       all     12.45      0.00      3.34     10.54     73.66
01:20:01 PM       all     12.14      0.00      3.46     11.44     72.97
01:30:01 PM       all     18.43      0.00      2.64     13.01     65.92
01:40:01 PM       all     14.97      0.00      3.54     11.34     70.14
01:50:02 PM       all     11.42      0.00      3.16      9.36     76.06
02:00:01 PM       all     10.74      0.00      1.81      8.49     78.96
02:10:01 PM       all     10.37      0.00      3.02      7.47     79.14
02:20:02 PM       all     11.69      0.00      3.49      9.86     74.96
02:30:01 PM       all      8.71      0.00      1.62      7.40     82.27
02:40:01 PM       all      9.92      0.00      3.21      8.60     78.26
02:50:02 PM       all      9.11      0.00      3.08      9.20     78.60
03:00:01 PM       all     12.38      0.00      2.12     11.28     74.22
03:10:01 PM       all     12.17      0.00      3.38      9.51     74.94
03:20:01 PM       all     10.21      0.00      3.17     10.73     75.90
03:30:01 PM       all     13.11      0.00      2.51     16.24     68.13
03:40:01 PM       all     13.11      0.00      3.22      8.39     75.28
03:50:01 PM       all      9.08      0.00      2.92      7.47     80.54
04:00:02 PM       all      7.51      0.00      1.43      5.94     85.12
04:10:02 PM       all     11.25      0.00      3.23     10.89     74.63
04:20:01 PM       all     12.52      0.00      3.62      9.57     74.29
04:30:01 PM       all      9.07      0.00      1.61      6.85     82.47
04:40:02 PM       all      8.86      0.00      2.80      7.74     80.61
04:50:01 PM       all      8.37      0.00      2.80      6.67     82.16
05:00:01 PM       all      9.10      0.00      1.38      6.17     83.34
05:10:01 PM       all     10.93      0.00      3.01      6.24     79.81
05:20:01 PM       all      8.60      0.00      3.48      7.52     80.40
05:30:01 PM       all      7.37      0.00      1.44      6.14     85.04
05:40:01 PM       all     10.30      0.00      3.03      6.79     79.88

05:40:01 PM       CPU     %user     %nice   %system   %iowait     %idle
05:50:01 PM       all      7.20      0.00      2.49      5.08     85.23
Average:          all     14.13      0.00      3.12     14.85     67.90