Bug 1891398

Summary: [RFE] Allow disabling mgr modules from always_on_modules
Product: [Red Hat Storage] Red Hat Ceph Storage Reporter: Prashant Dhange <pdhange>
Component: RADOSAssignee: Neha Ojha <nojha>
Status: NEW --- QA Contact: Manohar Murthy <mmurthy>
Severity: medium Docs Contact:
Priority: medium    
Version: 4.1CC: akupczyk, anharris, bhubbard, ceph-eng-bugs, nojha, rzarzyns, sseshasa, vereddy, vumrao
Target Milestone: ---Keywords: FutureFeature
Target Release: BacklogFlags: pdhange: automate_bug?
Hardware: x86_64   
OS: Linux   
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 1896587    
Bug Blocks: 1885216    

Description Prashant Dhange 2020-10-26 05:06:07 UTC 
Description of problem:
The ceph mgr modules like balancer or devicehealth should be allowed to disable. 

For example, the balancer module cannot be disabled :

The balancer is in *always_on_modules* and cannot be disabled(?). 

# ceph versions
{
    "mon": {
        "ceph version 14.2.8-91.el8cp (75b4845da7d469665bd48d1a49badcc3677bf5cd) nautilus (stable)": 3
    },
    "mgr": {
        "ceph version 14.2.8-91.el8cp (75b4845da7d469665bd48d1a49badcc3677bf5cd) nautilus (stable)": 3
    },
    "osd": {
        "ceph version 14.2.8-91.el8cp (75b4845da7d469665bd48d1a49badcc3677bf5cd) nautilus (stable)": 6
    },
    "mds": {
        "ceph version 14.2.8-91.el8cp (75b4845da7d469665bd48d1a49badcc3677bf5cd) nautilus (stable)": 1
    },
    "rgw": {
        "ceph version 14.2.8-91.el8cp (75b4845da7d469665bd48d1a49badcc3677bf5cd) nautilus (stable)": 1
    },
    "overall": {
        "ceph version 14.2.8-91.el8cp (75b4845da7d469665bd48d1a49badcc3677bf5cd) nautilus (stable)": 14
    }
}

# ceph mgr module ls|jq '.always_on_modules,.enabled_modules'
[
  "balancer",
  "crash",
  "devicehealth",
  "orchestrator_cli",
  "progress",
  "rbd_support",
  "status",
  "volumes"
]
[
  "dashboard"
]

# ceph mgr module disable balancer
Error EINVAL: module 'balancer' cannot be disabled (always-on)

# ceph mgr module disable balancer --force
Invalid command: unused arguments: ['--force']
mgr module disable <module> :  disable mgr module
Error EINVAL: invalid command

# ceph mgr module ls|jq '.always_on_modules,.enabled_modules'
[
  "balancer",
  "crash",
  "devicehealth",
  "orchestrator_cli",
  "progress",
  "rbd_support",
  "status",
  "volumes"
]
[
  "dashboard"
]


Version-Release number of selected component (if applicable):
14.2.8-91.el8cp

How reproducible:
Frequently

Steps to Reproduce:
1. Deploy ceph cluster
2. Try disabling balacer or devicehealth modules

Actual results:
Unable to disable modules from always_on_modules

Expected results:
Disabling modules from always_on_modules should be allowed

Additional info:
Comment 1 Neha Ojha 2020-10-28 15:11:16 UTC 
(In reply to Prashant Dhange from comment #0)
> Description of problem:
> The ceph mgr modules like balancer or devicehealth should be allowed to
> disable. 
> 
> For example, the balancer module cannot be disabled :
> 
> The balancer is in *always_on_modules* and cannot be disabled(?). 
> 
> # ceph versions
> {
>     "mon": {
>         "ceph version 14.2.8-91.el8cp
> (75b4845da7d469665bd48d1a49badcc3677bf5cd) nautilus (stable)": 3
>     },
>     "mgr": {
>         "ceph version 14.2.8-91.el8cp
> (75b4845da7d469665bd48d1a49badcc3677bf5cd) nautilus (stable)": 3
>     },
>     "osd": {
>         "ceph version 14.2.8-91.el8cp
> (75b4845da7d469665bd48d1a49badcc3677bf5cd) nautilus (stable)": 6
>     },
>     "mds": {
>         "ceph version 14.2.8-91.el8cp
> (75b4845da7d469665bd48d1a49badcc3677bf5cd) nautilus (stable)": 1
>     },
>     "rgw": {
>         "ceph version 14.2.8-91.el8cp
> (75b4845da7d469665bd48d1a49badcc3677bf5cd) nautilus (stable)": 1
>     },
>     "overall": {
>         "ceph version 14.2.8-91.el8cp
> (75b4845da7d469665bd48d1a49badcc3677bf5cd) nautilus (stable)": 14
>     }
> }
> 
> # ceph mgr module ls|jq '.always_on_modules,.enabled_modules'
> [
>   "balancer",
>   "crash",
>   "devicehealth",
>   "orchestrator_cli",
>   "progress",
>   "rbd_support",
>   "status",
>   "volumes"
> ]
> [
>   "dashboard"
> ]
> 
> # ceph mgr module disable balancer
> Error EINVAL: module 'balancer' cannot be disabled (always-on)

Have you tried to use "ceph balancer off"? That should do it.

> 
> # ceph mgr module disable balancer --force
> Invalid command: unused arguments: ['--force']
> mgr module disable <module> :  disable mgr module
> Error EINVAL: invalid command
> 
> # ceph mgr module ls|jq '.always_on_modules,.enabled_modules'
> [
>   "balancer",
>   "crash",
>   "devicehealth",
>   "orchestrator_cli",
>   "progress",
>   "rbd_support",
>   "status",
>   "volumes"
> ]
> [
>   "dashboard"
> ]
> 
> 
> Version-Release number of selected component (if applicable):
> 14.2.8-91.el8cp
> 
> How reproducible:
> Frequently
> 
> Steps to Reproduce:
> 1. Deploy ceph cluster
> 2. Try disabling balacer or devicehealth modules
> 
> Actual results:
> Unable to disable modules from always_on_modules
> 
> Expected results:
> Disabling modules from always_on_modules should be allowed
> 
> Additional info: