[Solved] Proxmox 6.3 DHCP Error on Huawei RH2288 V3 Servers: No Working Lease in Persistent Database

When booting the Proxmox VE 6.x installer on enterprise Huawei FusionServer RH2288 V3 rack servers, the graphical installation aborts and drops into a debug shell with the error: No working lease in persistent database.

Root Cause: Kernel framebuffer conflict with Huawei integrated server graphics (BMC) and IOMMU initialization.

Step-by-Step Resolution

1. At the Proxmox GRUB boot menu, press e to edit the boot entry.
2. Locate the linux kernel line and append the following kernel parameters:

   modprobe.blacklist=nouveau amd_iommu=on video=efifb:off

3. Press Ctrl+X or F10 to boot.

Assigning Static IP in Debug Shell (If DHCP is Unavailable)

If your datacenter environment does not offer DHCP on the management network, configure network parameters directly in the debug prompt:

ip addr add 192.168.1.50/24 dev enp2s0f0
ip route add default via 192.168.1.1 dev enp2s0f0
echo "nameserver 1.1.1.1" > /etc/resolv.conf

How to Fix VMware ESXi 6.0 Root Account Lockout and Brute-Force Restrictions

Starting with version 6.0, VMware ESXi introduced an automated security lockout feature that locks the root account after consecutive failed login attempts. On hypervisors exposed to public networks, malicious automated SSH bots frequently trigger this threshold, inadvertently locking legitimate administrators out of the vSphere Client and Web UI.

Security Best Practices: Enforce SSH key-based authentication • Restrict ESXi management firewall to designated administrative IPs.

1. Unlocking the Root Account via Local Console (DCUI)

Log in via the physical or out-of-band Direct Console User Interface (DCUI), navigate to Troubleshooting Options, enable the ESXi Shell, and reset the lockout counter:

# Check failed login attempt count
pam_tally2 --user root

# Reset failed attempt counter and unlock account
pam_tally2 --user root --reset

2. Permanent Hardening: Restrict Management Access

To eliminate unauthorized brute-force attempts permanently:

1. Disable SSH password logins in /etc/ssh/sshd_config:

   PasswordAuthentication no

2. Restrict the ESXi management firewall rule for the vSphere Client (port 443 / 902) to your office or VPN gateway IPs:

   esxcli network firewall ruleset set --ruleset-id vSphereClient --allowed-all false
   esxcli network firewall ruleset allowedip add --ruleset-id vSphereClient --ip-address 203.0.113.10

How to Install and Use zerofree on CentOS, RHEL, and Fedora to Compact VM Disks

When shrinking dynamic virtual machine disk images (such as VirtualBox VDI, VMware VMDK, or QEMU QCOW2), zeroing out unused filesystem blocks is essential for effective host compression. Because Enterprise Linux distributions (CentOS 6/7, RHEL) do not ship zerofree in their default package repositories, compiling from source is the quickest solution.

Environment: CentOS 6/7 • RHEL • Fedora • Ext3 / Ext4 Filesystems

1. Installing Build Headers and Compiling zerofree

Install the e2fsprogs development headers and compile:

yum install e2fsprogs-devel gcc make -y
cd /usr/src
wget http://frippery.org/uml/zerofree-1.0.3.tgz
tar -zxf zerofree-1.0.3.tgz
cd zerofree-1.0.3
make
cp zerofree /usr/bin/

2. Zeroing Out Unallocated Blocks

Important: Always remount the target filesystem in read-only mode prior to executing zerofree to prevent filesystem corruption:

# Remount filesystem as read-only:
mount -o remount,ro /

# Run zerofree on the target block partition:
zerofree -v /dev/sda1

Once complete, shut down the VM and run your hypervisor's disk compacting command (e.g. VBoxManage modifymedium --compact disk.vdi) on the host machine.