Red Hat Enterprise Virtualization 3.0 represents a major upgrade and now utilizes the power and stability of Red Hat Enterprise Linux 6.

Please ensure that your Red Hat Enterprise Linux 6 system is up to date before commencing an installation of, or upgrade to, Red Hat Enterprise Virtualization 3.0.

Do not use non-ASCII characters in Red Hat Enterprise Virtualization group and user names because Kerberos authentication supports only ASCII characters.

The Red Hat Enterprise Virtualization Hypervisor provides a locked down environment. You must allocate enough storage space for the hypervisor's internal use. In particular /data is used for storage of upgrade images and, where local storage is being used, virtual machine images. Please refer to the Red Hat Enterprise Linux Hypervisor Deployment Guide for more information.

After upgrading to 3.0, you also need to upgrade the guest agents for both Windows and Linux virtual machines.

When exporting virtual machines and templates, ensure the target storage domain has sufficient free disk space to hold the exported virtual machine. If insufficient disk space is available, the export operation will fail.

Do not use non-ASCII characters for snapshot names. The use of non-ASCII characters for snapshot names is not supported.

Login names that contain characters outside of the US-ASCII character set are not currently supported. This is a limitation imposed by the Java Runtime Environment.

The Red Hat Enterprise Virtualization Manager searches Active Directory users by first name and NT4 Security Accounts Manager (SAM) usernames. It does not search by User Principle Names (UPNs) of the form user@domain.

When using the VNC client with languages other than English, the keyboard layout is the same as for QEMU.

When working with an Active Directory LDAP server, all users, including administrators and standard users, must be bound and authenticated to log in. Kerberos pre-authentication is required on the Directory Server. It is not possible to authenticate users that are set not to require Kerberos pre-authentication in Active Directory.

The Red Hat Enterprise Virtualization Manager welcome page does not render correctly in Internet Explorer 9 when compatibility view is enabled.

To disable compatibility view for the Red Hat Enterprise Virtualization Manager click the Compatibility View button on the address bar while the site is loaded.

The REST API now includes a force action to assist with removal of a data center.

The Red Hat Enterprise Virtualization Manager setup script, rhevm-setup, supports the en_US.UTF-8, en_US.utf8, and en_US.utf-8 locales. Attempts at installation on systems where the locale in use is not one of these supported values will fail.

Occasionally, JBoss produces a timeout when trying to stop the jbossas service as part of the rhevm-upgrade process. When this is encountered you must manually issue the service jbossas stop command, as root, to stop the service before re-attempting the upgrade.

Upgrades from beta to GA will result in an incorrect partitioning of the host. You must cleanly install the GA version.

Installations on UEFI machines will finish successfully but fail to boot. To successfully boot a UEFI machine, configure it to boot using legacy mode for the device.

In some cases adding a Red Hat Enterprise Linux host fails on the first attempt with the error "ImportError: No module named config". If you encounter this error, re-attempt adding the host.

Due to the Enhanced Security Configuration (ESC), Internet Explorer versions 8 and 9 crash when attempting to download and install the required certificates to display the Red Hat Enterprise Virtualization Manager user interface. To work around this problem, add the "about:internet" page to the list of trusted websites to allow the required certificates to be added successfully.

The Red Hat Enterprise Virtualization GUI Certificate Installer removes its record for the Add/Remove Programs menu after it concludes operations. The Windows Program Compatibility Assistant consequently pops up because it incorrectly concludes that the installation failed. This problem can be avoided if the user clicks "Approve Installation Finished Successfully" to confirm a successful installation.

Automatic installation for the Certification Authorities (CA) certificate puts the certificate in the Intermediate CA directory instead of the Trusted Root CA directory. You can add a Trusted Root CA certificate two ways:

For more information about adding a Trusted Root CA certificate, see the following site:

http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/sag_cmuncertstor.mspx?mfr=true

Uniform Resource Locators (URLs) for the Administration Portal and User Portal are now case sensitive. If you have bookmarked or otherwise saved URLs to these sites that use alternative cases to the defaults, update your saved copies to use the default case.

The Red Hat Enterprise Virtualization Manager cannot perform live upgrades to the presentation layer of its administration user interface. Before upgrading the Red Hat Enterprise Virtualization Manager, close all open instances of the administration user interface. After the upgrade has completed, re-connect to the administration user interface to see the updated interface.

In some rare cases, the WPF clients may throw .NET exception when closing the browser tab/window in a time-out scenarios. To overcome this, close the browser and try again.

Edits of the management interface properties that require resetting the NIC are time consuming. As a result the edit dialog takes a long time to respond, The dialog is released only after the state of the network connection has been verified. This is the case even for successful operations.

Metadata about the agent tools is stored in a database that is local to the Red Hat Enterprise Virtualization Manager. On an ISO domain that is shared between multiple Red Hat Enterprise Virtualization Manager environments, the agent tools are available only on the manager that is used to upload the tools until the list of ISO images is updated. To update the list of ISO images, either click the refresh button or wait the amount of time that is specified for the AutoRepoDomainRefreshTime option in vds_options.

Red Hat Enterprise Virtualization Manager does not support the use of user accounts which are marked as expired in the directory server for the domain. This applies to both Active Directory and IPA domains.

The account's password must be changed in the directory server to re-enable the account before it is used with Red Hat Enterprise Virtualization Manager.

Power management parameters such as userid, password, and options are tested on a host by Red Hat Enterprise Virtualization Manager only when they are entered by the administrator. If the administrator chooses to ignore alerts about incorrect parameters, or if the parameters are changed on the power management hardware without a corresponding change in by Red Hat Enterprise Virtualization Manager, fencing fails and the host becomes non-responsive.

The Red Hat Enterprise Virtualization Manager requires at least one host in a cluster to have an Up status for fencing to be available. If no hosts in a cluster have an Up status, fencing is not available for that cluster.

When adding a host to a data center using FCP storage, you can activate the host even if a data storage domain in the data center is unavailable. After five minutes, Red Hat Enterprise Virtualization Manager sets the host to a status of "non-operational". If the host is manually re-activated, it is set to non-operational again after five minutes. This delay can create the illusion that the host is up when it in fact remains non-operational. To avoid hosts becoming non-operational because of this reason, ensure that the data storage domains for the data center are accessible before activating hosts.

Initialization scripts cannot handle network names that contain the - (hyphen) character, so choose network names that do not include the - character.

When the master storage domain moves to the Unknown status, Red Hat Enterprise Virtualization Manager initiates a process to reconstruct the storage domain. After this process is complete, the manager reverts the status of the storage domain to its state prior to becoming unknown, which can result in the storage domain having a status of Up when it is not actually functioning correctly. In this case, the domain will be set to inactive after five minutes. To avoid this problem, test the master storage domain after it has been reconstructed to ensure that it is functioning correctly.

Use of an export domain of a different type than the data center it is attached to is available but requires infrastructure support on the host. Where support is not available the export domain is liable to become inactive while exports are in progress. All hosts in the data center must have infrastructure support for the storage type presented by the export domain. Support for export domains on FCP and iSCSI will deprecate in future releases, so it is recommended that you use export domains on NFS instead.

Guest hibernation, through ram (S3) or disk (S4), does not function as expected in all cases. For example, resuming a guest can cause the guest agent to freeze. As a result it is currently recommended that you do not initiate hibernation from within virtual machines.

Templates in Red Hat Enterprise Virtualization carry over template parameters but not configuration parameters from the virtual machine that is used to create the template.

High Availability is an example of a configuration parameter in a virtual machine that is not carried over when you create a template. If you use a High Availability virtual machine to create a template, none of the virtual machines created from the template will be High Availability by default.

Windows virtual machines using virtio disks with drivers installed prior to Red Hat Enterprise Virtualization 2.2.7 are not able to run on Red Hat Enterprise Linux 6 hosts without the virtio drivers first being updated.

Consult the Red Hat Knowledge Base (http://kbase.redhat.com/) and User Groups (https://access.redhat.com/groups/red-hat-enterprise-virtualization-3x-private) for further information.

In Windows virtual machines, Red Hat Enterprise Virtualization Manager uses the Red Hat Enterprise Virtualization agent that is installed inside the guest to monitor the health and status of the virtual machine. Killing or stopping the agent abnormally can cause status information to be inaccurate.

When the "vmlinuz" and "initrd" options are added to the kernel boot for the "New", "Edit", or "Run Once" options under the Virtual Machines tab of the Red Hat Enterprise Virtualization Manager, virtual machines are always started with the Linux boot option even when the primary and secondary boot devices are explicitly set to "CD-ROM" and "Hard Drive".

In some instances, if you attempt to shut down a virtual machine from the User Portal, the status of the virtual machine is frozen at "Powering Down", which indicates that the virtual machine has not been completely shut down. The virtual machine is waiting for user input, such as clicking a button to confirm shutdown, so log into the virtual machine and shut it down gracefully.

Snapshots cannot handle multiple virtual disks if they were added after the virtual machine was initially created. Ensure all virtual disks are added when a virtual machine is created if you want to take snapshots of the disks.

The Single Sign On (SSO) is a recommended feature for Windows virtual desktops. However, the Single Sign On (SSO) feature and the Legal Notice caption are not simultaneously supported on virtual machines. To use SSO on a virtual machine, disable the Legal Notice caption. If you want to use the Legal Notice caption on the virtual machine, do not implement SSO.

Single Sign On (SSO) requires that either the Red Hat Enterprise Virtualization Manager and the virtual machine authenticate to the same directory services domain - be it Active Directory or IPA. Alternatively, where domain authentication is not used in the guest, the user defined in Red Hat Enterprise Virtualization Manager must have the same credentials as are defined for the user locally inside the virtual machine.

When upgrading the Windows guest tools from Red Hat Enterprise Virtualization 2.2 to 3.0, you need to restart Windows before you can use the updated tools.

The ad hoc report options of the Red Hat Enterprise Virtualization Manager Reports requires an extensive knowledge of the database internal structure as well as an understanding of the capabilities of JasperServer.

The history database cannot be migrated from Red Hat Enterprise Virtualization version 2.2 to 3.0.

The list of attached ISO images is set at the beginning of a SPICE session. If you add a new ISO image while the SPICE session is running, it will be added to the list of attached ISO images only after the SPICE session has been reinitiated. To refresh the list of ISO images, close and reopen the SPICE console.

The USB redirector transmits data between the client and the virtual desktop without authentication or encryption. When using USB redirection for sensitive material, note that the data is being transmitted in clear text.