Bug 1479838 - Wrong matching for LUN disks
Wrong matching for LUN disks
Product: ovirt-engine
Classification: oVirt
Component: BLL.Storage (Show other bugs)
Unspecified Unspecified
unspecified Severity high (vote)
: ovirt-4.2.0
: ---
Assigned To: Arik
Kevin Alon Goldblatt
: Regression
Depends On:
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Reported: 2017-08-09 10:17 EDT by Arik
Modified: 2017-11-28 12:09 EST (History)
4 users (show)

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Fixed In Version:
Doc Type: No Doc Update
Doc Text:
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Clone Of:
Last Closed:
Type: Bug
Regression: ---
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Verified Versions:
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oVirt Team: Virt
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---
rule-engine: ovirt‑4.2+
rule-engine: blocker+
ahadas: devel_ack+

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External Trackers
Tracker ID Priority Status Summary Last Updated
oVirt gerrit 80533 master MERGED core: fix matching of lun disks 2017-08-16 04:09 EDT

  None (edit)
Description Arik 2017-08-09 10:17:27 EDT
Description of problem:
In 4.2, the matching of the devices reported form libvirt with those defined in the database was moved from vdsm to the engine. But the logic that was introduced for matching the disks is incomplete. It is done according to the 'path' of the disk (like VDSM used to do), but assumes the following logic: the path must contain the disk id. 
However, this logic doesn't hold for LUN disks since their path is composed of "/dev/mapper/<lun_id>". Thus, we need to extend the matching logic for LUN disks, to base on the lun_id instead.

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

How reproducible:

Steps to Reproduce:
1. Run a VM with a plugged LUN disk

Actual results:
The LUN disk is being unplugged in the engine database

Expected results:
The LUN disk should remain plugged

Additional info:
If the disk is plugged after being unplugged in a previous run of the VM, the VM will start and the LUN disk will remain plugged. So in order to reproduce this bug, we'll need to enforce the devices hash to change by, for example, plugging a NIC.
Comment 1 Arik 2017-08-09 10:19:20 EDT
The fix is supposed to be relatively easy but it needs to be verified with LUN disks so this better gets handled by the storage team.
Comment 2 Red Hat Bugzilla Rules Engine 2017-08-14 04:35:05 EDT
This bug report has Keywords: Regression or TestBlocker.
Since no regressions or test blockers are allowed between releases, it is also being identified as a blocker for this release. Please resolve ASAP.
Comment 3 Kevin Alon Goldblatt 2017-11-28 12:09:54 EST
Verified with the following code:

Verified with the following scenario:
1. Created a vm, attached a direct LUN to the VM (LUN is plugged)
2. Started the vm (LUN is plugged)
3. Added nic (LUN remains plugged)

Moving to VERIFIED

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