Measuring disk I/O performance with mongoperf

By now, you should have a fair idea of the importance of disk I/O and how it directly impacts your database performance. MongoDB provides a nifty little utility called mongoperf that allows us to quickly measure disk I/O performance.

Getting ready

For this recipe, we only need the mongoperf utility, which is available in the bin directory of your MongoDB installation.

How to do it...

1. Measure the read throughput with mmf disabled:

root@ubuntu:~# echo "{ recSizeKB: 8, nThreads: 12, fileSizeMB: 10000, r: true, mmf: false }" | mongoperf

You will get the following result:

mongoperf use -h for help
parsed options:
{ recSizeKB: 8, nThreads: 12, fileSizeMB: 10000, r: true, mmf: false }
creating test file size:10000MB ...
1GB...
2GB...
3GB...
4GB...
5GB...
6GB...
7GB...
8GB...
9GB...
testing...
options:{ recSizeKB: 8, nThreads: 12, fileSizeMB: 10000, r: true, mmf: false }
wthr 12
new thread, total running : 1
read:1 write:0
19789 ops/sec 77 MB/sec
19602 ops...