Bug 2219524

Summary: [RFE] Raise a Warning when an EC pool is created with failure_domain as OSD
Product: [Red Hat Storage] Red Hat Ceph Storage Reporter: Pawan <pdhiran>
Component: RADOSAssignee: Radoslaw Zarzynski <rzarzyns>
Status: NEW --- QA Contact: Pawan <pdhiran>
Severity: medium Docs Contact:
Priority: unspecified    
Version: 6.1CC: bhubbard, ceph-eng-bugs, cephqe-warriors, nojha, vumrao
Target Milestone: ---Keywords: FutureFeature
Target Release: 6.1z2   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Pawan 2023-07-04 06:54:00 UTC 
Description of problem:
With the new provision of deploying EC pools ( 4+2, 4+3 ) on a 4 node cluster, Custom CRUSH rules become very important, without which, All the PGs could be placed on OSDs from same host, and losing a host might trigger data loss.


To tackle this, we need Raise a Warning when an EC pool is created with failure_domain as OSD, Warning the user of potential case of Data loss scenario.

Without Custom CRUSH rule, if a 4+2 pool is created on a 4 node cluster with failure domain OSD, we have observed that sometimes upto 4 OSDs from same host is picked for an acting set. If this node goes down, the data recovery is not possible.

We should have a warning generated when such EC profile based pools are created without Custom CRUSH rules.


Version-Release number of selected component (if applicable):


How reproducible:
always

Steps to Reproduce:
1. Deploy a 4 node RHCS cluster.
2. Create a 4+2 EC rule, with failure domain as OSD.
3. Create a pool, observe PG placement. 


Actual results:
No warnings generated for above scenario

Expected results:
Warnings to be generated for the issues.

Additional info: