Describe the issue:

[Doc] Update doc for OSD addition when Ceph reports HEALTH_ERR due to full OSDs. This doc bug is created to address https://bugzilla.redhat.com/show_bug.cgi?id=2231360#c52

Describe the task you were trying to accomplish:

Add capacity when ceph OSDs were full

Suggestions for improvement:



Document URL:
https://docs.redhat.com/en/documentation/red_hat_openshift_data_foundation/4.15/html/scaling_storage/requirements-for-scaling-storage-nodes#requirements-for-scaling-storage-nodes

Chapter/Section Number and Title:

Chapter 2. Requirements for scaling storage

Product Version:
ODF 4.16

Environment Details:
Adding capacity when OSDs are full

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

Additional information:
The section that conatins information about OSD getting full should also cover possible steps that can be performed as mentioned in https://bugzilla.redhat.com/show_bug.cgi?id=2231360#c52 

i.e, If storage capacity reaches full state (85% of total capacity), you can increase the 'full' ratio to 0.9 via the odf-cli tool and try to add capacity. Even after that, if osds are stuck in pending state or not coming up, stop all IO's, then increase the 'full' ratio again to 0.92 and wait for cluster rebalance to happen. Once cluster rebalance is complete, change the full ratio back to its original value of 0.85