What problems will happen when virt-who is down?

Environment

Red Hat Enterprise Linux 7
Red Hat Enterprise Linux 6

Issue

What problems will happen when virt-who is down?
Should we use virt-who in redundant configuration ?

Resolution

1. What problems will happen when virt-who is down?

The clients which existed before virt-who was down are NOT affected.
(The clients do not need to subscribe systems again after virt-who is up again. )

If you create new guests while virt-who is down, the new guests are affected because the information is not sent to RHN by virt-who. However, the impact will be limited, because the new clients can register the systems and update packages.

The problem is that the expiration date of the certificate of new clients is only seven days.

# subscription-manager list --consumed
+-------------------------------------------+
   Consumed Subscriptions
+-------------------------------------------+
Subscription Name:   Red Hat Enterprise Linux for Virtual Datacenters, Standard (DERIVED SKU)
Provides:            Red Hat Developer Toolset (for RHEL Server)
                     Oracle Java (for RHEL Server)
                     Red Hat Software Collections Beta (for RHEL Server)
                     Red Hat Enterprise Linux Server
                     Red Hat Software Collections (for RHEL Server)
                     Red Hat Beta
                     dotNET on RHEL (for RHEL Server)
SKU:                 RH00050
Contract:            10992560
Account:             5364511
Serial:              3914578433492149336
Pool ID:             8a85f9815551c36c015552a436583f81
Provides Management: Yes
Active:              True
Quantity Used:       1
Service Level:       Standard
Service Type:        L1-L3
Status Details:      Guest has not been reported on any host and is using a temporary unmapped guest <-- This is a warning meesage
Subscription Type:   Stackable (Temporary)  <------  Warning again! this is temporary
Starts:              09/30/15
Ends:                06/22/16    <------------------ only seven days
System Type:         Virtual

So, the new clients will need to re-attach after virt-who is up again.

2. Should we use virt-who in redundant configuration ?

From the above results, we think it depends on your operational system.

If you do not want to have the clients re-register after virt-who is up again, you should use virt-who in redundant configuration.

If you want to use virt-who in redundant configuration, you will be able to select one of the two ways below:

1. Run virt-who in multiple environments.
   (We can run virt-who in multiple environments at the same time for redundant configuration)

2. Run virt-who in a cluster systems.

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