Describe the issue:  
There is limited documented information on this QOS setting rbd_qos_iops_limit
in related to applying for an entire pool versus a particular image of that pool. 

Describe the task you were trying to accomplish:

Would like to have more concise clear documentation on this setting of rbd_qos_iops_limit and its effect on total pool IOPS limit versus per image IOS limit. 

Customer query:
If for example rbd_qos_iops_limit is set to 1000bps, is that limit applied for each RBD image separately such that no single image can go above 1000bps, or is it applied in total to the entire pool such that ALL IO for the pool is limited to 1000bps?

Suggestions for improvement:

Hoping to have more information in relation to  rbd_qos_iops_limit in Red Hat Documents 

with examples of 
a) Custom Per pool rbd_qos_iops_limit setting 
b) Custom Per Image rbd_qos_iops_limit setting
b) Custom Per pool rbd_qos_iops_limit setting + WITH subset of per image rbd_qos_iops_limit setting. Example: Per pool rbd_qos_iops_limit 10000 with Per Image rbd_qos_iops_limit { image1 1000, image2 2000 image3 4000 }
    
Document URL:
https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/4/html-single/block_device_guide/index

Chapter/Section Number and Title:
A.9. Block device configuration override options

Product Version: RHCS 4.2 

Environment Details:

Any other versions of this document that also needs this update:

Additional information:

The examples and details of for QOS setting rbd_qos_iops_limit need not be limited to the above Red Hat links mentioned, but in general any other upstream link as well
https://docs.ceph.com/en/latest/rbd/rbd-config-ref/#qos-settings