CODEWITHSUNDEEP
filesystemsstoragebenchmarking
mshamma
mshamma

Reputation: 337

In the bonnie benchmark, what does the latency result represent?

While trying to benchmark some NFS server using the bonnie benchmark, I noticed that one row of the results are latency values. I was wondering if anyone can explain what does this latency values represent. Thanks!

Sample bonnie results (Latency line emphasized):

mshamma@hs1:/mnt/hs18/bonnie$ sudo bonnie -u root -c 100 -s 100000
Using uid:0, gid:0.
Writing a byte at a time...done
Writing intelligently...done
Rewriting...done
Reading a byte at a time...done
Reading intelligently...done
start 'em...done...done...done...done...done...
Create files in sequential order...done.
Stat files in sequential order...done.
Delete files in sequential order...done.
Create files in random order...done.
Stat files in random order...done.
Delete files in random order...done.
Version  1.96       ------Sequential Output------ --Sequential Input- --Random-
Concurrency 100     -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
hs1         100000M   980  94 107439  10 57596   8  2426  93 126676   9 165.0  15
**Latency             11089us   22143ms   40946ms   18167us     204ms     240ms**
Version  1.96       ------Sequential Create------ --------Random Create--------
hs1                 -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16  1427   9    48   0   231   0  1244  10    52   0  2715  11
**Latency             22582us     406ms    6516ms    5665us   46629us   21379us**
1.96,1.96,hs1,100,1288943643,100000M,,980,94,107439,10,57596,8,2426,93,126676,9,165.0,15,16,,,,,1427,9,48,0,231,0,1244,10,52,0,2715,11,11089us,22143ms,40946ms,18167us,204ms,240ms,22582us,406ms,6516ms,5665us,46629us,21379us

Upvotes: 2

Views: 2371

Answers (1)

thejh
thejh

Reputation: 45578

Latency basically is the time needed to tell the harddisk what to do, to wait for the harddisk to move the head to the right location (if it isn't an SSD), and so on. If you take the time it takes to read/write something as a linear function of the amount of data, it's the Y-intercept.

Upvotes: 2

Related Questions