1. Ensure the host-based subscription is attached to the hypervisor. For details of provisioning hosts and virtual hosts, see the Red Hat Satellite 6 Provisioning Guide.
2. Install and configure the virt-who daemon. This document will guide you through the necessary steps.

1. A virtual machine is provisioned.
2. The virtual machine requests a subscription from Subscription Manager.
3. As the subscription manager doesn’t yet know to which host the virtual machine belongs, a temporary subscription is granted, valid for a maximum 24 hours.
4. The virt-who daemon connects to the virtualization manager or hypervisor and requests details of the guest virtual machines. By default, this request is made every hour, but the interval is configurable. Red Hat recommends this value remain at the default unless requested by Red Hat Support.
5. The virtualization manager or hypervisor returns to virt-who the list of guest virtual machines, including each UUID.
6. The virt-who daemon reports to Subscription Manager the list of guest virtual machines.
7. Subscription Manager then reconciles the subscriptions required by the virtual machines with those available. If the required subscriptions are available, they are assigned to the virtual machine and its subscription is complete.

1. Install Red Hat Enterprise Linux, version 7 (recommended) or 6.

   Only a CLI environment is required. For help with this step, see the Red Hat Enterprise Linux 7 Installation Guide or Red Hat Enterprise Linux 6 Installation Guide.

2. Register the Red Hat Enterprise Linux server to the Subscription Management Server:

   # subscription-manager register --username=admin --password=secret --org=organization_label --auto-attach

3. Open a network port for HTTPS:

   To enable virt-who to communicate with the subscription service, TCP port 443 must be opened.

   On Red Hat Enterprise Linux 7:

   # firewall-cmd --add-port="443/tcp"
   # firewall-cmd --add-port="443/tcp" --permanent

   On Red Hat Enterprise Linux 6:

   # iptables -A INPUT -m state --state NEW -p tcp --dport 443 -j ACCEPT
   # service iptables save

1. Install the virt-who package.

   # yum install virt-who

1. Create a Subscription Management user with Administrator access.

   This account is used to allow virt-who to connect to Subscription Management. Red Hat recommends the account be used for only this purpose. If you have previously created a Subscription Management user for this purpose, skip this step.

2. Encrypt the user’s password

   Encrypting the virt-who account password provides greater security compared with storing the password in plain text. The root account must encrypt the password because the encryption key is written into a file that is only readable by the root account. For that reason, only the root account can decrypt the password.

   1. Execute the virt-who-password utility.

      # virt-who-password

      Enter the password of the account to connect to the hypervisor. The encrypted form of the password is output to the screen.

      # virt-who-password
      Password: <virt who account's password>
      Use following as value for encrypted_password key in the configuration file:
      837a5d6a34203e805c998ce02bf84c03

   2. Make a note of the encrypted password.

1. Encrypt the password of the account to be used to connect to the Red Hat Enterprise Virtualization Manager instance.

   Use the virt-who-password command to encrypt the password. For an example, see Section 5.2, “Creating a User for virt-who”.

2. Copy the template configuration file to a new file.

   On the virt-who host:

   # cp /etc/virt-who.d/template.conf /etc/virt-who.d/rhevmhost1.conf

   To make it easy to identify the configuration file for each hypervisor, use the RHEV-H host’s name as the new file’s name. In this example, the host name is rhevmhost1.

3. Edit the configuration file you just created, changing the example values with those specific to your configuration.

   [rhevmhost1]              1
   type=rhevm                2
   hypervisor_id=hostname    3
   owner=org_label           4
   env=Library               5
   server=https://rhevmhost1.example.com:443  6
   username=admin@internal   7
   encrypted_password=bd257f93d@482B76e6390cc54aec1a4d  8

   1

   This must be unique for each virt-who instance. Use the Red Hat Virtualization Manager host’s name to make it easy to identify the configuration file for each hypervisor.

   2

   The type=rhevm specifies that this virt-who connection is to a Red Hat Virtualization Manager.

   3

   Specifies that hypervisors will be identified in the Subscription Management web UI by their host name. The default is to use the hypervisor’s UUID, which is less meaningful.

   4

   Organization’s label.

   5

   This specifies the environment in which the host will be placed and must be Library.

   6

   Red Hat Enterprise Virtualization Manager’s fully qualified host name or IP address. The default port number is 8443, but port 443 is used by Red Hat Enterprise Virtualization Manager after version 3.0.

   7

   Account name by which virt-who is to connect to the Red Hat Enterprise Virtualization Manager instance. The username option requires input in the format username@domain.

   8

   Encrypted password for the account specified by username.

Configure virt-who to connect to the Red Hat Enterprise Linux hypervisor

1. Configure the Red Hat Enterprise Linux hypervisor to register to the Subscription Asset Manager instance.

   # yum install http://rhsm.example.com/pub/candlepin-cert-consumer.noarch.rpm

2. Register the Red Hat Enterprise Linux hypervisor to the Subscription Asset Manager.

   # subscription-manager register --org="organizational_label"

3. Attach the VDC subscription to the Red Hat Enterprise Linux hypervisor.

   # subscription-manager attach --pool=subscription_pool_ID

   To find the required subscription pool ID, list all available subscriptions.

   # subscription-manager list --available

4. Copy the template configuration file to a new file.

   To make it easy to identify the configuration file for each hypervisor, use the hypervisor host’s name as the new file’s name. In this example, the host name is rhelhost1.

   cp /etc/virt-who.d/template.conf /etc/virt-who.d/rhelhost1.conf

5. Edit the configuration file you just created, changing the example values with those specific to your configuration.

   [rhelhost1.example.com]         1
   type=vdsm                       2
   hypervisor_id=hostname          3

   1

   Red Hat Enterprise Linux Hypervisor’s FQDN.

   2

   The type=vdsm parameter specifies that this virt-who connection is to a Red Hat Enterprise Linux hypervisor.

   3

   Specifies that hypervisors will be identified in the Subscription Management web UI by their host name. The default is to use the hypervisor’s UUID, which is less meaningful.

1. Configure the virtual machine to register with the Subscription Asset Manager.

   # yum install http://_rhsm.example.com_/pub/candlepin-cert-consumer.noarch.rpm

2. Register the virtual machine.

   # subscription-manager register --org="organization_label"

3. Obtain a subscription

   # subscription-manager attach --pool=subscription_pool_ID

   Ensure the subscription pool is the same as that used for the hypervisor. The virtual machine will obtain a subscription from the Subscription Asset Manager. For details of this process, see Section 1.4, “Virtual Machine Subscription Process”.

1. Encrypt the password of the account to be used to connect to the Red Hat Enterprise Virtualization Manager instance.

   Use the virt-who-password command to encrypt the password. For an example, see Section 5.2, “Creating a User for virt-who”.

2. Copy the template configuration file to a new file.

   To make it easy to identify the configuration file for each hypervisor, use the VMware vCenter host’s name as the new file’s name. In this example, the host name is vcenterhost1.

   # cp /etc/virt-who.d/template.conf /etc/virt-who.d/vcenterhost1.conf

3. Edit the configuration file you just created, changing the example values with those specific to your configuration.

   [vcenterhost1]          1
   type=esx                2
   hypervisor_id=hostname  3
   owner=org_label            4
   env=Library             5
   server=vcenterhost1.example.com  6
   username=corporate\svc-virt-who 7
   encrypted_password=bd257f93d@482B76e6390cc54aec1a4d  8

   1

   This must be unique for each virt-who instance. Use the VMware vCenter’s host name to make it easy to identify the configuration file for each hypervisor.

   2

   The type=esx parameter specifies that this virt-who connection is to a VMware vCenter.

   3

   Specifies that hypervisors will be identified in the Subscription Management web UI by their host name. The default is to use the hypervisor’s UUID, which is less meaningful.

   4

   Organization’s label.

   5

   This specifies the environment in which the host will be placed and must be Library.

   6

   VMware vCenter server’s fully qualified host name or IP address.

   7

   Account name by which virt-who is to connect to the hypervisor, in the format domain_name\account_name. Note that only a single backslash separates the values for domain_name and account_name. If you are using a domain account, and the global configuration file /etc/sysconfig/virt-who, then two backslashes are required. For further details, see Red Hat Knowledgebase solution How to use a windows domain account with virt-who for more information.

   8

   Encrypted password for the account specified by username.

1. Enable Windows Remote Management and either the HTTP or HTTPS listener must be running.

   On the Microsoft Hyper-V server:

   # winrm quickconfig

2. Enable remote administration on the Microsoft Hyper-V server.

   On the Microsoft Hyper-V server:

   # netsh advfirewall firewall set rule group="Remote Administration" new enable=yes

3. If you are using HTTP, enable the unencrypted connection.

   On the Microsoft Hyper-V server:

   # winrm set winrm/config/service @{AllowUnencrypted="true"}

4. Verify that the authentication method configured on the Microsoft Hyper-V server is either Basic or NTLM.

   On the Microsoft Hyper-V server:

   # winrm get winrm/config/service/auth

5. Encrypt the password of the account to be used to connect to the Microsoft Hyper-V server.

   Use the virt-who-password command to encrypt the password. For an example, see Section 5.2, “Creating a User for virt-who”.

6. Copy the template configuration file to a new file.

   On the virt-who host:

   # cp /etc/virt-who.d/template.conf /etc/virt-who.d/hypervhost1.conf

   To make it easy to identify the configuration file for each hypervisor, use the Microsoft Hyper-V server’s host name as the new file’s name. In this example, the host name is hypervhost1.

7. Edit the configuration file you just created, changing the example values with those specific to your configuration.

   [hypervhost1]                   1
   type=hyperv                     2
   hypervisor_id=hostname          3
   owner=org_label                 4
   env=Library                     5
   server=hypervhost1.example.com  6
   username=administrator          7
   encrypted_password=bd257f93d@482B76e6390cc54aec1a4d  8

   1

   This must be unique for each virt-who instance. Use the Microsoft Hyper-V host’s name to make it easy to identify the configuration file for each hypervisor.

   2

   The type=hyperv specifies that this virt-who connection is to a Microsoft Hyper-V host.

   3

   Specifies that hypervisors will be identified in the Subscription Management web UI by their host name. The default is to use the hypervisor’s UUID, which is less meaningful.

   4

   Organization’s label.

   5

   This specifies the environment in which the host will be placed and must be Library.

   6

   Microsoft Hyper-V fully qualified host name or IP address.

   7

   Account name by which virt-who is to connect to the hypervisor. By default this is Administrator. To use an alternate account, create a user account and assign that account to the following groups (Windows 2012 Server): Hyper-V Administrators and Remote Management Users.

   8

   Encrypted password for the account specified by username.

1. Configure virt-who service for Subscription Management.

   Edit the global /etc/sysconfig/virt-who configuration file and set the following parameter as shown. This specifies that virt-who is to be communicating with a Subscription Management host.

   VIRTWHO_SAM=1

   Warning

   By default virt-who initiates a scan hourly. The interval is defined by the VIRTWHO_INTERVAL global configuration parameter and measured in seconds. It should ONLY be changed on advice from Red Hat Support.

2. Allow for HTTP proxy between virt-who and guest virtual machines.

   If there is an HTTP proxy between the server on which virt-who is running and the hypervisors or virtualization managers, edit the global /etc/sysconfig/virt-who configuration file and set the following parameter as shown.

   http_proxy=http://proxy-ip-or-hostname:port-number

3. Verify the virt-who configuration.

   Run the command virt-who --one-shot which reads all configuration files, retrieves the list of virtual machines from all sources, then exits immediately. This tests the configuration files, credentials and connectivity to configured virtualization platforms.

   # virt-who --one-shot

   The output you can expect is a list of hypervisors and the hosted guest virtual machines, in JSON format. The following is an extract from virt-who output from a VMware vSphere instance. The output from all hypervisors follows the same structure.

   {
       "guestId": "422f24ed-71f1-8ddf-de53-86da7900df12",
       "state": 5,
       "attributes": {
           "active": 0,
           "virtWhoType": "esx",
           "hypervisorType": "vmware"
       }
   },

4. Start and enable the virt-who service.

   On Red Hat Enterprise Linux 7:

   # systemctl start virt-who.service
   # systemctl enable virt-who.service

   On Red Hat Enterprise Linux 6:

   # service virt-who start
   # chkconfig virt-who on

5. Verify that the virt-who service started successfully.

   On Red Hat Enterprise Linux 7:

   # systemctl status virt-who.service

   The output from this command should be similar to the following. The virt-who.service; enabled output confirms it is enabled and Active: active (running) confirms it is started.

   ● virt-who.service - Daemon for reporting virtual guest IDs to subscription-manager
      Loaded: loaded (/usr/lib/systemd/system/virt-who.service; enabled; vendor preset: disabled)
      Active: active (running) since Fri 2016-03-11 14:59:05 AEST; 47s ago

   On Red Hat Enterprise Linux 6:

   # service virt-who status

   The output from this command should be similar to the following.

   virt-who (pid  7474) is running...