Ceph: rbd bench Commands

Intro

The reference to these commands is from Sébastien Han Blog Post "Ceph: validate that the RBD cache is active" and the rbd man Page. For more posts about Ceph, take a look at Sébastien Han Blog.

Requisite - RBD image for running the Benchmarks

To be able to run a rbd benchmark, you need to create an image. The command to create an image for this would be:

$ RBD_IMAGE_NAME="bench1"
$ rbd create --size=10G $RBD_IMAGE_NAME

rbd bench

Flags

Takes normal rbd command flags like:

• -p or --pool for the rbd pool to use.

The following flags are for the benchmark configuration:

• --io-type if read or write IO should be run.
• --io-size how big every IO should be (in B/K/M/G/T).
• --io-threads how many IOs are done in parallel.
• --io-total how much total IO should be done.
• --io-pattern sequential or random IO pattern.

Benchmarks

Write Benchmark

For sequential write benchmark:

$ rbd -p replicapool bench $RBD_IMAGE_NAME --io-type write --io-size 8192 --io-threads 256 --io-total 10G --io-pattern seq

Read Benchmark

For sequential read benchmark:

$ rbd -p replicapool bench $RBD_IMAGE_NAME --io-type read --io-size 8192 --io-threads 256 --io-total 10G --io-pattern seq

Notes

• To use random IO instead of sequential IO pattern, change the --io-pattern flag value to rand.

Have Fun!