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Linux I/O analyze

Hi,

Could you please help me with an analyze of the following iostat values?
Are they OK or not?

Thank you!

 iostat 1 5
Linux 2.6.20.el5 (rhel)       01/20/2013

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           3.11    0.00    1.68    2.80    0.00   92.41

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
cciss/c0d0       24.56        48.23      2801.11 1547983563 89895579532
sda              26.35       585.62       445.13 18794097564 14285523912
sdb              22.04       358.39       314.24 11501842308 10084945384
sdc               2.02       588.96       131.76 18901538364 4228706256
sdd               5.26        30.16      3670.22  967906596 117788035744
sde               6.15       755.91       206.17 24259421068 6616592496
sdf              27.58      4781.98       210.51 153467543396 6755838408
dm-0             61.66       585.62       445.13 18794096452 14285523816
dm-1             43.90       358.39       314.24 11501841260 10084945368
dm-2             19.76       588.96       131.76 18901537388 4228706256
dm-3            459.45        30.16      3670.22  967905620 117788035688
dm-4             31.31       755.91       206.17 24259420092 6616592368
dm-5             60.23      4781.98       210.51 153467542284 6755838408

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           6.37    0.00    7.74    0.75    0.00   85.14

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
cciss/c0d0        3.00         0.00       208.00          0        208
sda              20.00        32.00       304.00         32        304
sdb              19.00        16.00       288.00         16        288
sdc               0.00         0.00         0.00          0          0
sdd               0.00         0.00         0.00          0          0
sde               2.00         0.00        32.00          0         32
sdf               2.00        32.00         0.00         32          0
dm-0             40.00        32.00       304.00         32        304
dm-1             37.00        16.00       288.00         16        288
dm-2              0.00         0.00         0.00          0          0
dm-3              0.00         0.00         0.00          0          0
dm-4              4.00         0.00        32.00          0         32
dm-5              2.00        32.00         0.00         32          0

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           6.99    0.00    8.36    1.37    0.00   83.27

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
cciss/c0d0        0.00         0.00         0.00          0          0
sda              62.00        56.00      1408.00         56       1408
sdb              35.00        32.00       496.00         32        496
sdc               0.00         0.00         0.00          0          0
sdd               0.00         0.00         0.00          0          0
sde               2.00         0.00       192.00          0        192
sdf              26.00        16.00       400.00         16        400
dm-0            180.00        56.00      1408.00         56       1408
dm-1             64.00        32.00       496.00         32        496
dm-2              0.00         0.00         0.00          0          0
dm-3              0.00         0.00         0.00          0          0
dm-4             24.00         0.00       192.00          0        192
dm-5             51.00        16.00       400.00         16        400

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           6.11    0.00    8.23    0.75    0.00   84.91

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
cciss/c0d0        0.00         0.00         0.00          0          0
sda              37.00        32.00       600.00         32        600
sdb              39.00        16.00       600.00         16        600
sdc               0.00         0.00         0.00          0          0
sdd               0.00         0.00         0.00          0          0
sde               4.00         0.00       128.00          0        128
sdf               1.00        16.00         0.00         16          0
dm-0             77.00        32.00       600.00         32        600
dm-1             76.00        16.00       600.00         16        600
dm-2              0.00         0.00         0.00          0          0
dm-3              0.00         0.00         0.00          0          0
dm-4             16.00         0.00       128.00          0        128
dm-5              1.00        16.00         0.00         16          0

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           9.02    0.00   14.29    2.38    0.00   74.31

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
cciss/c0d0       32.00         0.00      1200.00          0       1200
sda              24.00        16.00       384.00         16        384
sdb              24.00        16.00       384.00         16        384
sdc               0.00         0.00         0.00          0          0
sdd               0.00         0.00         0.00          0          0
sde               0.00         0.00         0.00          0          0
sdf               8.00        96.00        40.00         96         40
dm-0             49.00        16.00       384.00         16        384
dm-1             49.00        16.00       384.00         16        384
dm-2              0.00         0.00         0.00          0          0
dm-3              0.00         0.00         0.00          0          0
dm-4              0.00         0.00         0.00          0          0
dm-5             11.00        96.00        40.00         96         40

Open in new window




 iostat -xd 1 5


Device:         rrqm/s   wrqm/s   r/s   w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util
cciss/c0d0        1.22   326.94  1.37 23.19    48.23  2801.09   116.03     0.13    5.40   1.85   4.54
sda               1.50    33.81  4.52 21.83   585.61   445.13    39.12     0.04    1.69   1.29   3.40
sdb               0.92    20.93  3.69 18.35   358.39   314.24    30.51     0.03    1.29   1.04   2.28
sdc               1.61    16.14  1.68  0.34   588.96   131.77   357.19     0.03   14.78   2.45   0.49
sdd               0.04   454.13  0.63  4.63    30.16  3670.20   703.70     0.09   17.80   6.86   3.61
sde               2.07    23.09  3.47  2.68   755.91   206.17   156.35     0.02    2.81   1.70   1.05
sdf              14.54    18.11 19.37  8.21  4781.95   210.51   181.04     0.09    3.20   1.82   5.03
dm-0              0.00     0.00  6.02 55.64   585.61   445.13    16.72     0.01    2.34   0.55   3.40
dm-1              0.00     0.00  4.62 39.28   358.39   314.24    15.32     0.10    2.32   0.52   2.29
dm-2              0.00     0.00  3.29 16.47   588.96   131.77    36.47     0.11    5.65   0.25   0.49
dm-3              0.00     0.00  0.67 458.78    30.16  3670.20     8.05     0.06    0.05   0.08   3.61
dm-4              0.00     0.00  5.54 25.77   755.91   206.17    30.73     0.00    4.43   0.33   1.05
dm-5              0.00     0.00 33.91 26.31  4781.95   210.51    82.90     0.06    0.94   0.83   5.03

Device:         rrqm/s   wrqm/s   r/s   w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util
cciss/c0d0        0.00     4.00  0.00  4.00     0.00    64.00    16.00     0.04    9.00   6.50   2.60
sda               0.00    18.00  1.00 16.00    16.00   272.00    16.94     0.02    1.29   1.29   2.20
sdb               0.00     6.00  1.00 14.00    16.00   160.00    11.73     0.02    1.27   1.27   1.90
sdc               0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
sdd               0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
sde               0.00     3.00  0.00  1.00     0.00    32.00    32.00     0.00    2.00   2.00   0.20
sdf               0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
dm-0              0.00     0.00  1.00 34.00    16.00   272.00     8.23     0.04    1.17   0.66   2.30
dm-1              0.00     0.00  1.00 20.00    16.00   160.00     8.38     0.03    1.19   0.90   1.90
dm-2              0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
dm-3              0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
dm-4              0.00     0.00  0.00  4.00     0.00    32.00     8.00     0.01    2.00   0.50   0.20
dm-5              0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00

Device:         rrqm/s   wrqm/s   r/s   w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util
cciss/c0d0        0.00    70.00  8.00  8.00    64.00   624.00    43.00     0.10    6.38   3.81   6.10
sda               0.00    60.00  2.00 31.00    32.00   728.00    23.03     0.04    1.15   1.15   3.80
sdb               0.00    29.00  1.00 28.00    16.00   456.00    16.28     0.02    0.83   0.83   2.40
sdc               0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
sdd               0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
sde               0.00    15.00  0.00  1.00     0.00   128.00   128.00     0.00    1.00   1.00   0.10
sdf               0.00     8.00  0.00  8.00     0.00   128.00    16.00     0.01    0.88   0.88   0.70
dm-0              0.00     0.00  2.00 91.00    32.00   728.00     8.17     0.10    1.04   0.41   3.80
dm-1              0.00     0.00  1.00 57.00    16.00   456.00     8.14     0.04    0.74   0.41   2.40
dm-2              0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
dm-3              0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
dm-4              0.00     0.00  0.00 16.00     0.00   128.00     8.00     0.02    1.00   0.06   0.10
dm-5              0.00     0.00  0.00 16.00     0.00   128.00     8.00     0.01    0.88   0.44   0.70

Device:         rrqm/s   wrqm/s   r/s   w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util
cciss/c0d0        0.00    36.00  0.00  6.00     0.00   336.00    56.00     0.08   13.17   7.33   4.40
sda               0.00    13.00  4.00 28.00    64.00   328.00    12.25     0.04    1.31   1.28   4.10
sdb               0.00    13.00  1.00 28.00    16.00   328.00    11.86     0.03    0.97   0.97   2.80
sdc               0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
sdd               0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
sde               0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
sdf               0.00     0.00  2.00  0.00    32.00     0.00    16.00     0.01    6.00   6.00   1.20
dm-0              0.00     0.00  4.00 41.00    64.00   328.00     8.71     0.05    1.18   0.91   4.10
dm-1              0.00     0.00  1.00 41.00    16.00   328.00     8.19     0.04    0.98   0.67   2.80
dm-2              0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
dm-3              0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
dm-4              0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
dm-5              0.00     0.00  2.00  0.00    32.00     0.00    16.00     0.01    6.00   6.00   1.20

Device:         rrqm/s   wrqm/s   r/s   w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util
cciss/c0d0        0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
sda               1.00    18.00  3.00 21.00    48.00   312.00    15.00     0.04    1.46   1.46   3.50
sdb               0.00    16.00  1.00 23.00    16.00   312.00    13.67     0.02    1.00   0.92   2.20
sdc               0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
sdd               0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
sde               0.00    18.00  0.00  7.00     0.00   200.00    28.57     0.01    0.86   0.86   0.60
sdf               0.00     9.00  6.00  2.00    96.00    88.00    23.00     0.03    3.88   3.88   3.10
dm-0              0.00     0.00  4.00 39.00    48.00   312.00     8.37     0.06    1.30   0.81   3.50
dm-1              0.00     0.00  1.00 39.00    16.00   312.00     8.20     0.03    0.82   0.55   2.20
dm-2              0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
dm-3              0.00     0.00  0.00  0.00     0.00     0.00     0.00     0.00    0.00   0.00   0.00
dm-4              0.00     0.00  0.00 25.00     0.00   200.00     8.00     0.02    0.84   0.24   0.60
dm-5              0.00     0.00  6.00 11.00    96.00    88.00    10.82     0.04    2.35   1.82   3.10

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0
g0all
Asked:
g0all
2 Solutions
 
Chris SandriniSenior System EngineerCommented:
Hi

I don't see bad numbers but it is also difficult to guess. Your disk utilisation seem to be ok. Which means you are not using a lot of disk I/O

Why exactly are you asking this question? Do you have any issues?

I would run iostat -xkd 60 for a while. It gives you the output in kilobytes and not in blocks.

Also a nice reading:
http://bhavin.directi.com/iostat-and-disk-utilization-monitoring-nirvana/
0
 
odintsovCommented:
Hello,

Provided iostat output not useful. I will recommend using this form: iostat -x. Take a look
at last column (%util), it show current load of disk device.

Example:
iostat  -x
Linux 2.6.32-279.19.1.el6.x86_64 (es1.fastvps.ru)       25.01.2013       _x86_64(8 CPU)

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           0,12    0,00    0,33    0,07    0,00   99,49

Device:         rrqm/s   wrqm/s     r/s     w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util
sdb               0,61     0,09    1,06    0,64    41,04     4,47    26,81     0,01    5,97   5,31   0,90
sda               0,64     0,08    1,37    0,65   117,58     4,47    60,51     0,01    4,98   4,37   0,88
md2               0,00     0,00    2,20    0,55   155,94     4,10    58,25     0,00    0,00   0,00   0,00
md1               0,00     0,00    0,06    0,00     0,46     0,00     7,97     0,00    0,00   0,00   0,00

Main metric about IO overload it is iowait, it your output iowait is so small, 2.80 its fine, your disk system is non overloaded and has very big performance reserve.
0
 
g0allAuthor Commented:
I will return additional information.
0

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