Installation guide

When virtual NICs are configured to use DHCP, a setting controls whether DHCP sets the default route and
host name in addition to installing an IPv4 address. In ESX this setting is PEERDNS. In ESXi, the setting is
DhcpDNS. The PEERDNS value for ESX Service Console virtual NICs is migrated to the DhcpDNS setting for
the ESXi virtual NICs. The DhcpDNS setting preserves the ESX configuration for default route and host name
as well as the IPv4 address.
The migration from ESX 4.x to ESXi 5.0 also preserves manually assigned IPv4 and IPv6 addresses, default
route, and host-specific IPv4 and IPv6 routes.
When you upgrade from ESXi 4.x to ESXi 5.x, the default maximum number of ports for a virtual switch changes
from 64 to 128. To keep the same maximum number of ports that you have in ESXi 4.x, set the value explicitly
before you upgrade, using the vSphere Client.
ESX hosts have two IP stacks, one for the vmkernel and one for the Service Console. Because ESXi hosts have
only one IP stack, the migration cannot preserve both ESX default routes. After migration, the ESX Service
Console default route becomes the single ESXi default route, replacing the vmkernel route. The change to a
single ESXi default route might cause loss of connectivity for routed nonmanagement traffic that originates
from vmkernel. To restore vmkernel networking, you can configure static routes in addition to the default
route.
All vswif interfaces are migrated to vmk interfaces. If a conflict is detected between two interfaces, one is left
in disabled state. The upgrade disables any conflicting kernel IP addressing in favor of the management
interface.
The migration to ESXi 5.0 disables any existing vmk virtual NIC that meets the following conditions.
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The vmk virtual NIC has a manually configured (static) IP address.
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The IP address is in the same subnet as a vswif virtual NIC that is being migrated to a switch containing
the vmk virtual NIC.
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The vmk and vswif NICs are both on the same virtual switch.
For example, if vswif0, with IP address 192.0.2.1/24 on vswitch1, is migrated to a switch containing vmk0, with
IP address 192.0.2.2/24, also on vswitch1, after the migration, vmk0 will be disabled.
ESX 4.x Service Console Port Group Removed in Migration to ESXi 5.0
Because ESXi 5.0 has no Service Console, migrating from ESX 4.x to ESXi 5.0 removes the Service Console port
group.
After the migration to ESXi 5.0, a new port group, the Management Network port group, is created.
If any of your ESX hosts require the Service Console port group to support an existing service, you can write
a firstboot script to recreate the port group after the migration. See the information on the %firstboot command
in “Installation and Upgrade Script Commands,” on page 112.
Partitioning Changes from ESX 4.x to ESXi 5.0
The ESXi partition scheme used in ESXi 5.0 differs from that of earlier ESX and ESXi versions. ESXi 5.0 does
not have the Service Console partition found in ESX.
How these changes affect your host depends on whether you are upgrading to ESXi 5.0 or performing a fresh
installation.
vSphere Upgrade
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