sar -b

[kishore_11_1]

Hi
The output of the command sar -b is as below
the %rcache is showing as o
$ sar -b 10 10

HP-UX rchunx21 B.11.23 U ia64 07/26/10

03:25:45 bread/s lread/s %rcache bwrit/s lwrit/s %wcache pread/s pwrit/s
03:25:55 9355 7394 0 506 447 0 0 0
03:26:05 8915 7302 0 513 621 17 0 0
03:26:15 8865 7135 0 317 345 8 0 0
03:26:25 7918 6037 0 334 346 3 0 0
03:26:35 9562 6501 0 384 404 5 0 0
03:26:45 7813 5866 0 426 442 4 0 0
03:26:55 7184 4805 0 399 403 1 0 0
03:27:05 8518 5181 0 369 458 20 0 0
03:27:15 9436 9191 0 333 378 12 0 0
03:27:25 9829 9176 0 261 404 35 0 0

[Kapil Jha]

I suppose ur disk is heavely used, how much is your buffer cache.

what does
#sar -d says.

Glance?? is it the situation for long time.

BR,
Kapil+

[kishore_11_1]

Its happening for few days the output of sar -d is

04:21:51 device %busy avque r+w/s blks/s avwait avserv
04:21:52 c2t6d0 1.98 0.50 5 79 0.00 11.47
c5t6d0 1.98 0.50 5 79 0.00 9.94
c48t0d2 1.98 0.50 50 1331 0.00 0.32
c50t0d2 1.98 0.50 50 1362 0.00 0.49
c50t0d3 27.72 0.50 146 24285 0.00 3.50
c48t0d3 25.74 0.50 144 21418 0.00 2.90
c50t0d5 0.99 0.50 2 32 0.00 3.79
c48t0d5 1.98 0.50 2 32 0.00 11.75
c48t0d7 15.84 0.50 136 4800 0.00 1.20
c50t0d7 11.88 0.50 129 4040 0.00 0.97
c48t1d1 0.99 0.50 1 16 0.00 6.87
c50t1d1 0.99 0.50 2 32 0.00 6.43
c50t1d2 4.95 0.50 2 32 0.00 20.97
c48t1d2 0.99 0.50 2 32 0.00 6.32
c50t1d3 0.99 0.50 1 16 0.00 9.81
c48t1d5 0.99 0.50 4 253 0.00 0.50
c50t1d5 0.99 0.50 5 269 0.00 1.55
c50t1d6 0.99 0.50 1 16 0.00 7.03
c48t1d7 0.99 0.50 2 32 0.00 3.72
c50t1d7 2.97 0.50 3 48 0.00 9.57
c50t2d0 1.98 0.50 2 32 0.00 8.84
c48t2d0 0.99 0.50 1 16 0.00 3.32
c48t2d1 2.97 0.50 4 63 0.00 6.15
c50t2d1 4.95 0.50 8 127 0.00 6.37
c50t2d2 1.98 0.50 3 48 0.00 7.50
c48t2d2 0.99 0.50 2 32 0.00 6.84
c48t2d3 0.99 0.50 3 48 0.00 5.08
c48t2d5 16.83 0.50 20 333 0.00 8.44
c50t2d5 14.85 0.50 15 238 0.00 10.41
c50t2d6 79.21 0.51 172 3945 0.03 7.23
c48t2d6 72.28 0.50 168 4008 0.00 7.74
c52t0d1 0.99 0.50 1 16 0.00 0.28
c53t0d1 1.98 0.50 3 48 0.00 4.47
c53t0d2 0.99 0.50 2 32 0.00 4.55
c52t0d2 1.98 0.50 3 48 0.00 5.21
c52t0d3 0.99 0.50 2 32 0.00 4.95
c53t0d3 0.99 0.50 2 32 0.00 5.69
c52t0d4 0.99 0.50 2 32 0.00 4.49
c52t0d5 0.99 0.50 4 63 0.00 2.55
c53t1d0 0.99 0.50 1 16 0.00 0.40
c52t1d0 1.98 0.50 2 32 0.00 10.09
c52t1d1 8.91 0.50 20 554 0.00 6.29
c53t1d1 11.88 0.50 20 491 0.00 7.91
c52t1d2 2.97 0.50 3 48 0.00 7.58
c53t1d4 1.98 0.50 7 111 0.00 3.15
c52t1d4 4.95 0.50 2 32 0.00 28.99
c52t1d5 5.94 0.50 7 111 0.00 9.00
c53t1d5 0.99 0.50 3 48 0.00 1.85
c53t1d6 0.99 0.50 2 32 0.00 6.73
c52t1d6 0.99 0.50 3 48 0.00 3.23
c52t2d0 1.98 0.50 2 32 0.00 7.33
c52t2d1 1.98 0.50 5 79 0.00 5.41
c53t2d2 0.99 0.50 2 32 0.00 3.82
c52t2d3 1.98 0.50 2 32 0.00 7.89
c53t2d3 2.97 0.50 3 48 0.00 8.62
c53t2d4 1.98 0.50 6 95 0.00 3.67
c52t2d4 2.97 0.50 7 111 0.00 4.20
c53t2d5 2.97 0.50 1 16 0.00 35.67
c52t2d6 0.99 0.50 1 16 0.00 9.84
c52t2d7 1.98 0.50 2 32 0.00 10.76
c53t3d0 1.98 0.50 3 48 0.00 6.51
c52t3d1 11.88 0.50 25 396 0.00 5.48
c53t3d1 11.88 0.50 19 301 0.00 6.13
c53t3d2 16.83 0.50 23 364 0.00 7.15
c52t3d2 21.78 0.50 24 380 0.00 9.17
c52t3d3 0.99 0.50 2 32 0.00 5.76
c52t3d4 1.98 0.50 3 48 0.00 6.22
c53t3d5 0.99 0.50 2 32 0.00 6.53
c53t3d6 2.97 0.50 4 63 0.00 7.52
c52t3d6 2.97 0.50 6 95 0.00 5.35
c52t3d7 0.99 0.50 4 285 0.00 3.56
c53t3d7 1.98 0.50 5 285 0.00 4.76
c53t4d0 3.96 0.50 17 729 0.00 3.82
c52t4d0 3.96 0.50 13 523 0.00 4.48
c52t4d1 0.99 0.50 8 253 0.00 3.20
c53t4d1 1.98 0.50 9 475 0.00 5.10
c53t4d2 0.99 0.50 4 63 0.00 3.19
c52t4d2 2.97 0.50 7 111 0.00 4.38
c52t4d3 5.94 0.50 7 111 0.00 7.87
c53t4d3 5.94 0.50 2 32 0.00 28.31
c53t4d4 16.83 0.50 33 792 0.00 7.56
c52t4d4 14.85 0.50 28 586 0.00 7.18
c52t4d5 0.99 0.50 1 16 0.00 7.20
c53t4d6 8.91 0.50 9 143 0.00 9.64
c52t4d6 1.98 0.50 4 63 0.00 5.29
c52t4d7 3.96 0.50 5 79 0.00 8.22
c53t4d7 7.92 0.50 9 143 0.00 9.63
c53t5d0 14.85 0.50 20 428 0.00 8.89
c52t5d0 8.91 0.50 13 285 0.00 7.27
c52t5d1 10.89 0.50 14 222 0.00 8.41
c53t5d1 2.97 0.50 9 143 0.00 4.21
c52t5d2 4.95 0.50 4 63 0.00 12.25
c52t5d3 2.97 0.50 4 63 0.00 7.30
c53t5d3 2.97 0.50 4 63 0.00 8.13
c52t5d4 0.99 0.50 3 48 0.00 3.64
c53t5d6 0.99 0.50 1 16 0.00 5.64
c52t5d6 0.99 0.50 1 16 0.00 8.64
c53t6d0 0.99 0.50 1 16 0.00 8.35
c52t6d0 2.97 0.50 3 48 0.00 10.84
c52t6d1 0.99 0.50 2 32 0.00 4.18
c53t6d1 0.99 0.50 2 32 0.00 5.98
c53t6d2 0.99 0.50 1 16 0.00 6.78
c52t6d3 18.81 0.50 73 1172 0.00 2.63
c53t6d3 12.87 0.50 50 808 0.00 2.50
c53t6d4 0.99 0.50 2 32 0.00 4.09
c52t6d4 1.98 0.50 3 48 0.00 9.15
c52t6d5 0.99 0.50 1 16 0.00 0.36
c53t6d6 0.99 0.50 1 16 0.00 8.49
c52t6d6 0.99 0.50 3 48 0.00 3.25
c52t6d7 0.99 0.50 1 16 0.00 9.34
c53t6d7 0.99 0.50 1 16 0.00 5.37
c52t7d0 0.99 0.50 1 16 0.00 6.47
c52t7d1 0.99 0.50 1 16 0.00 7.26
c53t7d1 0.99 0.50 1 16 0.00 8.52
c52t7d2 1.98 0.50 5 79 0.00 4.57
c52t7d3 3.96 0.50 4 63 0.00 9.40
c53t7d4 0.99 0.50 3 48 0.00 3.76
c52t7d4 5.94 0.50 11 174 0.00 5.09
c52t7d5 1.98 0.50 2 32 0.00 8.71
c53t7d6 10.89 0.50 31 966 0.00 5.44
c52t7d6 10.89 0.50 28 824 0.00 5.56
c52t7d7 0.99 0.50 2 32 0.00 3.37
c53t7d7 1.98 0.50 3 48 0.00 7.41
c53t8d0 5.94 0.50 13 475 0.00 4.89
c52t8d0 4.95 0.50 15 396 0.00 3.56
c53t8d1 2.97 0.50 9 364 0.00 8.25
c53t8d2 1.98 0.50 5 269 0.00 10.42
c52t8d2 3.96 0.50 8 301 0.00 10.28
c52t8d3 2.97 0.50 5 79 0.00 5.11
c53t8d3 0.99 0.50 3 48 0.00 3.99
c53t8d4 2.97 0.50 4 63 0.00 6.84
c52t8d5 3.96 0.50 6 95 0.00 5.09
c53t8d5 1.98 0.50 3 48 0.00 5.96
c53t8d6 3.96 0.50 7 111 0.00 6.48
c52t8d6 3.96 0.50 7 111 0.00 5.29
c52t8d7 1.98 0.50 3 48 0.00 6.69
c52t9d0 0.99 0.50 2 32 0.00 3.07
c52t9d1 1.98 0.50 5 79 0.00 5.61
c53t9d1 4.95 0.50 6 95 0.00 8.20
c53t9d2 2.97 0.50 4 63 0.00 7.16
c52t9d2 1.98 0.50 6 95 0.00 3.44
c52t9d3 1.98 0.50 3 48 0.00 5.23
c53t9d3 2.97 0.50 6 190 0.00 4.77
c53t9d4 0.99 0.50 5 301 0.00 5.21
c52t9d4 2.97 0.50 7 301 0.00 6.64
c52t9d5 0.99 0.50 3 48 0.00 4.04
c53t9d6 46.53 0.50 195 5133 0.00 3.07
c52t9d6 42.57 0.50 214 5481 0.00 2.68
c52t10d0 0.99 0.50 4 63 0.00 3.60
c52t10d1 1.98 0.50 3 48 0.00 5.63
c53t10d1 4.95 0.50 2 32 0.00 22.83
c52t10d2 0.99 0.50 2 32 0.00 0.22
c52t10d3 1.98 0.50 2 32 0.00 9.35
c53t10d3 0.99 0.50 2 32 0.00 5.99
c53t10d4 1.98 0.50 2 32 0.00 8.94
c52t10d4 1.98 0.50 3 48 0.00 7.63
c53t10d6 7.92 0.50 16 444 0.00 5.16
c52t10d6 9.90 0.50 24 586 0.00 4.77
c52t10d7 0.99 0.50 2 32 0.00 5.32
c53t10d7 0.99 0.50 3 48 0.00 5.43
c52t11d0 0.99 0.50 1 16 0.00 6.91
c52t11d1 0.99 0.50 3 48 0.00 5.17
c53t11d1 0.99 0.50 2 32 0.00 3.05
c53t11d2 2.97 0.50 5 79 0.00 5.66
c52t11d2 0.99 0.50 2 32 0.00 4.79
c53t11d3 0.99 0.50 1 16 0.00 10.20
c52t11d5 0.99 0.50 11 317 0.00 1.09
c53t11d5 0.99 0.50 8 285 0.00 2.40
c52t11d6 3.96 0.50 4 63 0.00 10.35
c53t12d0 0.99 0.50 2 32 0.00 6.61
c52t12d0 0.99 0.50 1 16 0.00 14.50
c53t12d1 0.99 0.50 1 16 0.00 8.01
c52t12d2 0.99 0.50 1 16 0.00 0.29
c53t12d4 4.95 0.50 3 48 0.00 16.79
c52t12d4 0.99 0.50 3 48 0.00 2.94
c52t12d5 4.95 0.50 1 16 0.00 42.24
c53t12d5 0.99 0.50 2 32 0.00 4.81
c53t12d6 64.36 0.50 271 14907 0.00 6.43
c52t12d6 75.25 0.50 260 14875 0.00 6.57
c52t12d7 2.97 0.50 10 349 0.00 3.56
c53t12d7 0.99 0.50 6 285 0.00 3.89
c53t13d0 1.98 0.50 4 63 0.00 6.58
c52t13d0 5.94 0.50 8 127 0.00 7.08
c52t13d2 0.99 0.50 2 32 0.00 2.58
c52t13d3 18.81 0.50 39 871 0.00 7.90
c53t13d3 18.81 0.50 37 713 0.00 6.45
c53t13d4 0.99 0.50 7 317 0.00 2.77
c52t13d4 4.95 0.50 10 380 0.00 4.70
c53t13d5 0.99 0.50 1 16 0.00 11.44
c53t13d6 1.98 0.50 4 63 0.00 3.66
c52t13d6 4.95 0.50 9 143 0.00 6.41
c52t13d7 0.99 0.50 3 48 0.00 4.48
c53t13d7 1.98 0.50 2 32 0.00 8.99
c53t14d0 2.97 0.50 2 32 0.00 10.54
c52t14d0 5.94 0.50 3 48 0.00 19.83
c53t14d2 6.93 0.50 10 158 0.00 6.78
c52t14d2 4.95 0.50 4 63 0.00 12.44
c52t14d3 0.99 0.50 2 32 0.00 5.11
c53t14d3 0.99 0.50 1 16 0.00 7.99
c53t14d4 0.99 0.50 2 32 0.00 4.46
c52t14d4 7.92 0.50 2 32 0.00 40.30
c52t14d5 0.99 0.50 3 48 0.00 5.30
c53t14d5 2.97 0.50 4 63 0.00 6.81
c53t14d6 11.88 0.50 11 174 0.00 11.51
c52t14d6 7.92 0.50 9 143 0.00 8.87
c52t14d7 0.99 0.50 1 16 0.00 6.72
c53t14d7 2.97 0.50 6 95 0.00 4.89
c53t15d0 0.99 0.50 2 32 0.00 7.01
c52t15d0 0.99 0.50 2 32 0.00 8.37
c52t15d1 2.97 0.50 4 63 0.00 7.39
c53t15d1 0.99 0.50 2 32 0.00 8.39
c53t15d2 1.98 0.50 2 32 0.00 10.44
c52t15d2 3.96 0.50 3 48 0.00 15.07
c53t15d4 10.89 0.50 17 269 0.00 6.03
c52t15d4 17.82 0.50 26 412 0.00 6.97
c52t15d5 4.95 0.50 8 127 0.00 6.77
c53t15d5 4.95 0.50 5 79 0.00 11.12
c57t0d3 3.96 0.50 6 95 0.00 7.09
c56t0d3 3.96 0.50 8 127 0.00 5.20
c56t0d4 0.99 0.50 1 16 0.00 4.27
c56t1d1 0.99 0.50 1 16 0.00 11.51
c56t1d3 0.99 0.50 1 16 0.00 6.80
c57t1d5 0.99 0.50 1 16 0.00 9.19
c56t1d5 0.99 0.50 1 16 0.00 4.55
c56t1d7 0.99 0.50 1 16 0.00 7.50
c56t2d0 6.93 0.50 10 349 0.00 8.48
c57t2d0 5.94 0.50 12 412 0.00 6.91
c56t2d3 0.99 0.50 1 16 0.00 7.63
c56t2d4 0.99 0.50 1 16 0.00 9.36
c57t2d5 0.99 0.50 4 253 0.00 2.47
c56t2d5 0.99 0.50 4 301 0.00 2.29
c57t2d6 0.99 0.50 1 16 0.00 8.68
c57t2d7 0.99 0.50 2 32 0.00 6.01
c57t3d1 3.96 0.50 77 2075 0.00 0.41
c56t3d1 4.95 0.50 87 2139 0.00 0.57
c56t3d2 2.97 0.50 90 2471 0.00 0.41
c57t3d2 2.97 0.50 74 1743 0.00 0.43

[Deepankar Panda]

Hi... From your sar -b report,
You can surely check the %rcache & %wcache.. which are 4th and 7th column.. You can check that.. Most Buffer cache hit ratio for reading (%rcache) are 0 and Most Buffer cache hit ratio for write are non zero.. so there is a issue..

This can be controlled by kernel parameter
dbc_min_pct & dbc_max_pct if you are using dynamic buffer. %rcache has to be 100%.
%wcache has to be 70% or better.
%wcache Buffer cache hit ratio for write requests e.g., 1 - bwrit/lwrit;

%rcache Buffer cache hit ratio for read requests e.g., 1 - bread/lread;

The sar -b reports the number of transactions to block or physical devices. Always remember ,

the "bread" and "bwrite" column don't refer to the number of bytes/blocks transferred, but
refer to the number of transers (or transactions) to a block device.
The "pread" and "pwrite" refer to the number of transactions made to a physical or raw device.

Idealy we want to see an average %wcache of 95% or greater. If your system consistently gives
%wchache lower than 75% it always adviseable to lower the value of dbc_max_pct.

It is adviseable to always keep buffer cache lower or equal to 300MB.

Thanks,
Hope this Helps