Ceph: Designing and Implementing Scalable Storage Systems

Reproducing the problem

In order to aid understanding of the problem in more detail, the following steps will demonstrate how to create an erasure-coded profile that will require more shards than our three node cluster can support.

Firstly, like earlier in the chapter, create a new erasure profile but modify the K/M parameters to be k=3 and m=1:

    $ ceph osd erasure-code-profile set broken_profile k=3 m=1    plugin=jerasure technique=reed_sol_van

Now, create a pool with it:

    $ ceph osd pool create broken_ecpool 128 128 erasure broken_profile

The preceding command gives the following result:

If we look at the output from ceph -s, we will see that ...