VxVM enable failed: License has expired

When you work with Veritas Storage Foundation then you need a valid key. Otherwise you might encounter the following message:

VxVM vxconfigd ERROR V-5-1-1589 enable failed: License has expired or is not available for operation
        transactions are disabled.

To list all installed licenses run vxlicrep. Depending on your amount of keys, time and date you might get a more or less long list. Instead of running vxlicrep you can run vxlicrep with the -si option to get a short list of all valid keys:

# vxlicrep -si
Symantec License Manager vxlicrep utility version 3.02.51.010
Copyright (C) 1996-2010 Symantec Corporation. All rights reserved.
Creating a report on all VERITAS products installed on this system
vxlicrep ERROR V-21-3-1003 There are no valid VERITAS License keys installed in the system.

Looks like there is no valid key. Now it would be a good idea to list all keys:

# vxlicrep
Symantec License Manager vxlicrep utility version 3.02.51.010
Copyright (C) 1996-2010 Symantec Corporation. All rights reserved.
Creating a report on all VERITAS products installed on this system
...
   Product Name                        = VERITAS Storage Foundation for Cluster File System
   Key                                 = Invalid, Key EXPIRED -177 days ago
   License Type                        = NFR
...
 -----------------***********************-----------------

   Product Name                        = VERITAS File System
   License Type                        = DEMO
...
 -----------------***********************-----------------

   Product Name                        = VERITAS Volume Manager
   License Type                        = DEMO
...

And so on and so on. So, what happened? Somebody installed a demo key on this machine and as long as the machine was turned he coould work with Veritas volumes etc. After a reboot the system recognized an invalid key and refuses to bring the volumes back online. Time to install a valid key:

# vxlicinst
Symantec License Manager vxlicinst utility version 3.02.51.010
Copyright (C) 1996-2010 Symantec Corporation. All rights reserved.
Enter your license key : XXXX-XXXX-XXXX-XXXX-XXXX-XXXX-XXXX
...
License key successfully installed for VERITAS File System
License key successfully installed for VERITAS Volume Manager
...

Start the volumes to check if the key really works:

# vxvol startall
...
# vxprint
...

And reboot the machine to see if still everything works after a reboot (eg. Solaris):

# init 6

Btw. you can find all keys under /etc/vx/licenses/lic/. You can remove any invalid key by deleting the file with the invalid key in it's name.