Environment Audit & Inventory
Every migration starts with a precise inventory. Without a complete picture of your VMware environment, safe migration planning is impossible. At this stage we collect all data necessary for downstream architectural decisions.
What we collect during the audit
- Full VM list: vCPUs, RAM, disks (thin/thick), snapshots, VMware Tools version
- Network topology: vSwitches, port groups, VLANs, vDS (distributed switches)
- Storage configuration: NFS/iSCSI/VMFS datastores, RDM policies
- Application dependencies between machines (network traffic mapping)
- Backup schedule and retention (Veeam, NetBackup, native VMware)
- Licenses and versions: vCenter, ESXi, vSAN, NSX — what is in use
- SLA requirements and maintenance windows for each production system
Pro tip: Identify VMs with a large number of snapshots or RDM disks — these require special handling during conversion and may extend the migration timeline.
Proxmox VE Architecture Design
Based on the collected data, we design the target Proxmox environment. The key decisions are: storage model, network configuration, and HA strategy. Good architecture at this stage eliminates 90% of operational issues post-migration.
Storage model selection
Three main options: Local-ZFS (simplicity, high I/O performance), ZFS Shared + RoCE (dedicated ZFS server with iSCSI/NFS — recommended), NFS/iSCSI (SAN) (integration with existing infrastructure). We recommend a dedicated ZFS server exporting storage via iSCSI or NFS, with an RDMA over Converged Ethernet (RoCE) network — latencies of 1–5 µs with minimal CPU overhead.
Network configuration
Proxmox supports Linux bridges, VLAN-aware bridges, bonding (LACP/active-backup), and SDN. We map VMware vSwitches to their Linux equivalents — port groups with VLAN IDs become bridge ports with vlan_id.
HA Cluster with Corosync
Proxmox Cluster Manager (pmxcfs) requires a minimum of 3 nodes for quorum. Proxmox's built-in pve-ha-manager stack (CRM + LRM) on top of Corosync manages automatic VM failover — no Pacemaker or external agents. We configure watchdog, fencing, and restart policies in line with client SLAs.
Storage recommendation: dedicated ZFS server + RoCE v2. 25/100 GbE NICs with RDMA support (e.g. NVIDIA/Mellanox ConnectX-5 or ConnectX-6) — latencies of 1–5 µs with minimal CPU overhead thanks to hardware offload. Full live VM migration without stopping, I/O performance comparable to local NVMe, full HA redundancy.
Cluster Installation & Configuration
Proxmox VE is installed from an ISO image (Debian-based). A typical node installation takes about 15 minutes. After installation we configure storage, networking, and integrate with external systems: LDAP/AD, monitoring, backup.
| Component | VMware (equivalent) | Proxmox VE | Configuration time |
|---|---|---|---|
| Hypervisor | ESXi | Proxmox VE + KVM | ~15 min/node |
| Cluster management | vCenter | Proxmox Web UI / pvecm | ~30 min |
| Shared storage | vSAN / SAN | ZFS + RoCE / NFS / iSCSI | ~2–4h (ZFS server) |
| Virtual networking | vDS / vSS | Linux Bridge + VLAN SDN | ~1h |
| Backup | Veeam / VDP | Proxmox Backup Server | ~1h |
| Monitoring | vROps | Prometheus + Grafana | ~2h |
| Authentication | vSphere SSO | LDAP / AD integration | ~30 min |
We configure and test the Proxmox environment before beginning VM migration. VMware remains fully operational throughout — that is our safety net.
VM Conversion: virt-v2v
The primary tool for converting VMware machines to KVM format is virt-v2v — an open-source tool from the libguestfs project. It converts VMDK disks to qcow2/raw format and automatically installs virtio drivers in the guest OS.
Supported operating systems
- Windows Server 2008 R2 / 2012 / 2016 / 2019 / 2022 / 2025
- RHEL / CentOS / Rocky Linux / AlmaLinux 7, 8, 9
- Ubuntu 18.04 / 20.04 / 22.04 / 24.04 LTS
- Debian 10, 11, 12
- SUSE Linux Enterprise Server 12, 15
- Oracle Linux 7, 8, 9
Watch out for RDM disks: Raw Device Mappings require a separate approach — we convert them to passthrough disks or replace them with a storage-level solution before migration.
Live Migration — Near-Zero Downtime
For production systems we use a delta-sync technique: we copy data while the VM is running, then perform a short differential sync. The VM is only shut down for the final delta transfer — typically under 2 minutes. If the application runs on two or more VMs behind a load balancer (HAProxy, F5, etc.), downtime is zero — we migrate one VM at a time while the load balancer continuously routes traffic to the remaining available instances.
Initial sync (VM online)
We copy the disk image to Proxmox while the VM is running (VM remains accessible). For a 500 GB disk on a 10GbE link this takes ~7 minutes. The VM operates normally throughout.
Delta sync — brief freeze
We stop the VM for the block-level delta transfer (changed blocks only). Under typical production load the delta is 0.5–3% of disk size. For a 500 GB disk — delta ~2 GB — the transfer takes approximately 20–90 seconds.
Start on Proxmox + UAT
We start the VM on Proxmox and run automated acceptance tests (ping, port check, application health endpoint). VMware remains shut down but ready for rollback throughout the UAT window.
Validation & VMware Decommission
The final stage — but the most important from a safety perspective. We decommission VMware only after confirming the stability of the Proxmox environment. The standard observation period before closing the VMware license is 30–90 days.
- 24/7 monitoring for a minimum of 2 weeks after all VMs have been migrated
- PBS backup verification — at least 3 successful full + incremental cycles
- HA failover tests — node failure simulation in a maintenance window
- Review of alerts and performance metrics (Prometheus/Grafana)
- IT admin team training on the new environment
- Documentation of the new architecture and operational runbooks
- Formal VMware license closure / end of Broadcom subscription
Rollback always possible: Until the ESXi hosts are formally shut down, the VMware environment remains operational. Reverting to VMware in case of a critical issue takes minutes — simply change DNS or switch routing.
Ready to migrate?
We will conduct a free audit of your VMware environment and prepare a detailed migration plan with cost estimates and a timeline.
⚡ Free Environment Analysis → Financial Analysis