measure I/o disk

io_disk-measurement.txt

vcap@agent-id-pcfdev-0:~$ while true ; do iostat -p sda -x ; sleep 1 ;done
Linux 4.2.0-42-generic (agent-id-pcfdev-0) 	02/09/2017 	_x86_64_	(16 CPU)

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           0.80    0.00    4.49    0.10    0.00   94.61

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await r_await w_await  svctm  %util
sda               0.19    28.61    4.30   15.53   262.87  1166.64   144.22     1.07   53.79   19.09   63.40   3.64   7.21
sda1              0.19    28.61    4.28   15.37   262.78  1166.64   145.49     1.06   54.18   19.17   63.93   3.65   7.18
sda2              0.00     0.00    0.01    0.00     0.04     0.00     8.34     0.00    0.34    0.34    0.00   0.34   0.00

Linux 4.2.0-42-generic (agent-id-pcfdev-0) 	02/09/2017 	_x86_64_	(16 CPU)

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           0.80    0.00    4.49    0.10    0.00   94.61

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await r_await w_await  svctm  %util
sda               0.19    28.61    4.30   15.53   262.85  1166.57   144.21     1.07   53.79   19.09   63.40   3.64   7.21
sda1              0.19    28.61    4.28   15.37   262.77  1166.57   145.48     1.06   54.18   19.17   63.92   3.65   7.18
sda2              0.00     0.00    0.01    0.00     0.04     0.00     8.34     0.00    0.34    0.34    0.00   0.34   0.00

^C
vcap@agent-id-pcfdev-0:~$ for i in `seq 1 5` ; do echo ; dd bs=1M count=256 if=/dev/zero of=test conv=fdatasync ; done

256+0 records in
256+0 records out
268435456 bytes (268 MB) copied, 0.615035 s, 436 MB/s

256+0 records in
256+0 records out
268435456 bytes (268 MB) copied, 0.690325 s, 389 MB/s

256+0 records in
256+0 records out
268435456 bytes (268 MB) copied, 0.607005 s, 442 MB/s

256+0 records in
256+0 records out
268435456 bytes (268 MB) copied, 0.595528 s, 451 MB/s

256+0 records in
256+0 records out
268435456 bytes (268 MB) copied, 0.621414 s, 432 MB/s