Operating system patching at the branch office or data center for virtual servers installed on iSCSI LUNs
You can continue to use the same or existing methodologies and tools to perform patch management on physical or virtual branch servers booted over the WAN using product appliances.
If you want to perform virtual server patching at the data center and save a round-trip of patch software from the data center to the branch office, use this procedure:
1. At the branch office, power down the virtual machine, and take the VMFS datastore offline.
2. At the data center, take the LUN on the Core offline, and mount the LUN to a temporary ESX server.
3. Power up the virtual machine, and apply patches and file system updates.
4. Power down the virtual machine, take the VMFS datastore offline, and bring the LUN on the Core online.
5. At the branch office, bring the VMFS datastore online, and boot up the virtual machine.
If the LUN was previously pinned at the edge, patching at the data center can potentially invalidate the cache. If this is the case, you might need to prepopulate the LUN.