RHEV and RHCVA Cheat Sheet

On this page, I am publishing the notes I took while learning for the RHCVA exam (which is about RHEV). Please note these notes do not contain formal or technical details of the exam; Red Hat strictly forbids to talk about such things.

However, if you are learning for the RHCVA exam aswell you might find my notes useful.

The sources of my notes are the official RHEV guides which can be obtained here: https://access.redhat.com/knowledge/docs/Red_Hat_Enterprise_Virtualization/?locale=en-US

Official objectives for the RHCVA exam

  • Install Red Hat Enterprise Virtualization Manager and any dependencies.
  • Use Red Hat Enterprise Virtualization Manager to:
    Create datacenters and clusters.
    Manage hypervisor hosts.
    Configure storage.
    Create Red Hat Enterprise Linux and Microsoft Windows virtual machines.
    Develop pools and templates.
    Set up Red Hat Enterprise Virtualization Manager users.
  • Install and configure a Red Hat Virtualization Hypervisor to support guests and attach to a Red Hat Enterprise Virtualization Manager.
  • Import installation media for creating new virtual machines.
  • Perform management tasks, such as collecting logs, creating bookmarks for specific events, and more.

Install Red Hat Enterprise Virtualization Manager and any dependencies.
Make sure you have access to all repos and your system is up to date. Afterwards run the following commands with root permissions:

yum install rhevm rhevm-reports
rhevm-setup
  Stop ovirt-engine: yes
  Overwrite httpd config: yes
  HTTP Port: 80
  HTTPS Port: 443
  FQDN: <FQDN>
  Password for local RHEV admin: SECRET
  Organization: <company>
  Default storage type: NFS
  DB type: local
  Local datebase (engine) password: SECRET
  Configure NFS share to be used as an ISO Domain: yes
  Local ISO domain path: /some/path
  Configure iptables: no (or yes, as you like)

rhevm-manage-domains -action=add -domain=your-domain.tld -user=<user> -provider=<Provider> -interactive
#  <enter password>

rhevm-dwh-setup
rhevm-reports-setup

# Not necessary, but just to be sure...
/etc/init.d/ovirt-engine restart

You should now be able to access your RHEV-M under the FQDN provided above (browser URL).

Use Red Hat Enterprise Virtualization Manager to:
Create datacenters and clusters.

Simply add datacenters and clusters in the web interface of the RHEV-M.

Manage hypervisor hosts.
Nothing special here. You can use the RHEV-M for approving or deleting hosts. Furthermore you can put them in maintenance mode so you can move them between different data centers.

Configure storage.
Afaik there are three different types for storage domains (= types of storage): ISO domains (for iso files), data domains (for VMs, Templates, Snapshots) and export domains (for temporary data, such as VMs to be exported).
The data domain must be of the same type as the data center storage type (mostly iSCSI or NFS).

Create Red Hat Enterprise Linux and Microsoft Windows virtual machines.
New VMs can be created within the RHEV-M. There is a special mode called “run once” which lets you attach ISO files for the first run. You can use that ability for attaching your installation media. At the next stop & start of the VM the attached media will be gone.

Develop pools and templates.
A new pool can be added in the RHEV-M _after_ you created a template out of a VM. When you created a VM and installed an operating system, you are able to use the ability “Make Template” (can be found in the context menu when right-clicking on a VM).
Please note that a VM contains host-specific configurations, such as a host name or MAC address. It is wise to remove that information before you make a template out of this VM.

When creating a new pool, you have to select an existing VM template. After adding the pool, the provided amount of VMs will be created automatically. They are all based on the template you provided.

Find more information about VM sealing (=removing host-specific information) here: https://access.redhat.com/knowledge/docs/en-US/Red_Hat_Enterprise_Virtualization/3.1/html-single/Administration_Guide/index.html#sect-Sealing_Templates_in_Preparation_for_Deployment

Set up Red Hat Enterprise Virtualization Manager users.
When being logged in to the RHEV-M, you can find a “configure” button at the upper right of the screen. There you can find the user and role management. It should be self-explaining.

Install and configure a Red Hat Virtualization Hypervisor to support guests and attach to a Red Hat Enterprise Virtualization Manager.
A new hypervisor can be installed via PXE or a provided boot medium. There are two different types of RHEV-Hs: Thin (“bare-bone”) and thick (RHEL + RHEV tools).

I don’t know which hypervisor you are going to install during the exam so I can’t provide any notes here. But you can always have a look at the official guides (see link at the beginning of this cheat sheet).

After having installed a new hypervisor, you either need to approve it in the RHEV-M (thin host) or you need to add it manually (thick host).

Import installation media for creating new virtual machines.
New installation media (.iso files) should be placed in the ISO domain of the selected data center. They can be attached afterwards to VMs.

Perform management tasks, such as collecting logs, creating bookmarks for specific events, and more.

Configure RHEV-M with the following tool:

rhevm-config
  -l, --list (List all available configuration keys.)
  -a, --all (List all available configuration values.)
  -g, --get <key> (Display the value of a specific configuration key.)
  -s, --set <key>=<value> (Set rhe value of a specific configuration key)
  --cver (Config versionieren, per default ist alles "general").

# Example:
rhevm-config -l |grep -i timeout
rhevm-config -g UserSessionTimeOutInterval
rhevm-config -s UserSessionTimeOutInterval=1
rhevm-config -g UserSessionTimeOutInterval
service ovirt-engine restart

Collect log files with the following tool:

 rhevm-log-collector
 #(Part of the rhevm-log-collector package.)
 
rhevm-log-collector
rhevm-log-collector list
rhevm-log-collector collect

Some examples for using the search bar within the RHEV-M:

Hosts: VMs.status = up
VMs:
VMs: test
VMs: sortby uptime desc
Events: severity > normal sortby time
VMs: os = rhel6x64
Hosts: Tag = Test-Tag
VMs: os=unassigned or os=rhel6x64

Please note that there is an alternative to manually editing stuff in the RHEV-M: rhevm-shell
I recommend to have a look at the rhevm-shell by browsing through the official Red Hat guides.

Bookmarks can be created within the RHEV-M by performing a search (search bar) and then clicking on the bookmark bar at the left side of the screen. You can add a new bookmark by storing the current search string.

That’s already it! I know that this is not much, but those are parts of the quick notes I took when learning for the exam.
If you need to practice with RHEV you can either use the trial version from Red Hat or oVirt, the open source project. Here is a link to a guide (thanks Toby for the heads up!):
http://blog.jebpages.com/archives/up-and-running-with-ovirt-3-1-edition/

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