When you upgrade to ESX 4.0/ESXi 4.0, the host upgrade process preserves many components of the ESX 3.x/ESXi 3.5 configuration.

For ESXi, the upgrade to ESXi 4.0 preserves almost all configuration data, including your networking, security, and storage configuration. When you upgrade from ESXi 3.x to ESXi 4.0 the only configuration not preserved is related to licensing, because a new ESXi 4.0 license is required after the upgrade.

For ESX, the upgrade reuses the existing /boot partition to hold the ESX 4.0 boot files.

After the upgrade from ESX 3.x, the ESX 3.x installation is mounted in the new ESX 4.0 installation under the /esx3-installation directory.

The upgrade to ESX 4.0 preserves almost all configuration data, including your networking, security, and storage configuration. When you upgrade from ESX 3.x to ESX 4.0 the only configuration not preserved is related to licensing, because a new ESX 4.0 license is required after the upgrade. Specifically, the upgrade to ESX 4.0 preserves the following files from the ESX 3.x file system.

/etc/logrotate.conf

/etc/localtime

/etc/ntp.conf

/etc/syslog.conf

/etc/sysconfig/ntpd

/etc/sysconfig/xinetd

/etc/sysconfig/console

/etc/sysconfig/i18n

/etc/sysconfig/clock

/etc/sysconfig/crond

/etc/sysconfig/syslog

/etc/sysconfig/keyboard

/etc/sysconfig/mouse

/etc/ssh

/etc/nsswitch.conf

/etc/yp.conf

/etc/krb.conf

/etc/krb.realms

/etc/krb5.conf

/etc/login.defs

/etc/pam.d

/etc/hosts.allow

/etc/hosts.deny

/etc/ldap.conf

/etc/openldap

/etc/sudoers

/etc/snmp

/usr/local/etc

/etc/rc.d/rc*.d/*

/etc/xinetd.conf

/etc/motd

/etc/initiatorname.vmkiscsi

/etc/vmkiscsi.conf

Note

To migrate other files, consider using a postupgrade script. For example, you might want to create a script that copies the .ssh directory for root. The creation of custom scripts is beyond the scope of this manual.