Bug 1862534

Summary: [RFE] Add config to override disk propagation errors
Product: [oVirt] ovirt-engine Reporter: shubha <shubha.kulkarni>
Component: Tools.ConfigAssignee: Tal Nisan <tnisan>
Status: CLOSED CURRENTRELEASE QA Contact: Evelina Shames <eshames>
Severity: medium Docs Contact:
Priority: unspecified    
Version: 4.3.6.6CC: bugs, gveitmic, sfishbai
Target Milestone: ovirt-4.4.4Keywords: FutureFeature
Target Release: ---Flags: pm-rhel: ovirt-4.4?
pm-rhel: planning_ack?
pm-rhel: devel_ack+
pm-rhel: testing_ack+
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Engine now allows to override the default error propagation policy of disks by changing the PropagateDiskErrors config value
 Story Points: ---
Clone Of: Environment:
Last Closed: 2020-12-21 12:36:08 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: Storage RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 1314160    

Description shubha 2020-07-31 16:12:36 UTC 
Description of problem:
In OVirt, we have a property propagate_error at the disk level that decides in case of an error, how this error be propagated to the VM. 
This value is maintained in the database table with the default value set as Off. The default setting(Off) results in a policy that ends up pausing the VM rather than propagating the errors to VM.  There is no provision in the UI currently to configure this property for disk 
(images or luns). So there is no easy way to set this value.  Further, even if the value is manually set to "On" in db, it gets overwritten by UI every time some other property is updated as described here -
https://bugzilla.redhat.com/show_bug.cgi?id=1669367

Setting the value to "Off" is not ideal since it puts serious restrictions for the DR situation and unlike VMWare * Hyper-V, oVirt is not able to support the DR functionality - 
https://bugzilla.redhat.com/show_bug.cgi?id=1314160

While we wait for RFE, the proposal here is to allow a change in behavior via engine config. New engine config "PropagateDiskErrors" should be used to override the behavior.

Version-Release number of selected component (if applicable):
4.3.6

How reproducible:
Desirable behavior as described above.


Additional info:
https://lists.ovirt.org/archives/list/devel@ovirt.org/thread/YY56B5LCNO6ROSUPDWWHGKGUQVOLHCAR/
Comment 1 shubha 2020-07-31 18:18:28 UTC 
I have a fix for this and would like post for review. I am waiting for the appropriate previleges.
Comment 2 RHEL Program Management 2020-07-31 18:59:28 UTC 
The documentation text flag should only be set after 'doc text' field is provided. Please provide the documentation text and set the flag to '?' again.
Comment 4 Evelina Shames 2020-12-02 16:13:12 UTC 
Verified on ovirt-engine-4.4.4.2-0.1.el8ev.noarch with the following steps:

1. Create VM with direct lun
2. On engine run engine-config -s PropagateDiskErrors=true and restart engine service.
3. Run the VM
4. Search in engine.log for the DumpXml and verify that error_policy='report' for the direct lun instead of 'stop'
5. power off the VM
6. On engine set PropagateDiskErrors back to false (default) - engine-config -s PropagateDiskErrors=false and restart engine service.
7. Run the VM
8. Search in engine.log for the DumpXml and verify that error_policy='stop'.

Moving to 'Verified'.
Comment 5 Sandro Bonazzola 2020-12-21 12:36:08 UTC 
This bugzilla is included in oVirt 4.4.4 release, published on December 21st 2020.

Since the problem described in this bug report should be resolved in oVirt 4.4.4 release, it has been closed with a resolution of CURRENT RELEASE.

If the solution does not work for you, please open a new bug report.