Bug 1955123

Summary: [ovn][migration] 4K ports/networks validation before migrating to ML2/OVN if the target overlay is VXLAN
Product: Red Hat OpenStack Reporter: Daniel Alvarez Sanchez <dalvarez>
Component: python-networking-ovnAssignee: OSP Team <rhos-maint>
Status: NEW --- QA Contact: Eran Kuris <ekuris>
Severity: low Docs Contact:
Priority: low    
Version: 16.1 (Train)CC: apevec, egarciar, gregraka, gurpsing, jamsmith, jlibosva, lhh, majopela, scohen
Target Milestone: betaKeywords: FutureFeature
Target Release: ---Flags: gurpsing: needinfo? (dalvarez)
Hardware: Unspecified   
OS: Unspecified   
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Description Daniel Alvarez Sanchez 2021-04-29 13:39:22 UTC 
The VXLAN implementation for ML2/OVN poses a limitation of 4K networks and 4K ports per network. If the user selects VXLAN as the target overlay for the ML2/OVN migration, the migration process should validate that the cloud is suitable before attempting the migration. If it doesn't qualify, the user needs to reconsider the migration or use Geneve as the target overlay.

Please, note that for the validation, VLAN and flat networks must be excluded from the 4K limits.

There should be also a warning and the control plane should be fenced to avoid creating resources beyond the limits between the validation and the migration itself.