System information
Mounting VMFS Datastores with Existing Signatures
You might not have to resignature a VMFS datastore copy. You can mount a VMFS datastore copy without
changing its signature.
For example, you can maintain synchronized copies of virtual machines at a secondary site as part of a disaster
recovery plan. In the event of a disaster at the primary site, you can mount the datastore copy and power on
the virtual machines at the secondary site.
IMPORTANT You can mount a VMFS datastore only if it does not collide with an already mounted VMFS
datastore that has the same UUID.
When you mount the VMFS datastore, ESX/ESXi allows both reads and writes to the datastore residing on the
LUN copy. The LUN copy must be writable. The datastore mounts are persistent and valid across system
reboots.
Because ESX/ESXi does not allow you to resignature the mounted datastore, unmount the datastore before
resignaturing.
Mount a VMFS Datastore with an Existing Signature
If you do not need to resignature a VMFS datastore copy, you can mount it without changing its signature.
Prerequisites
Before you mount a VMFS datastore, perform a storage rescan on your host so that it updates its view of LUNs
presented to it.
Procedure
1 Log in to the vSphere Client and select the server from the inventory panel.
2 Click the Configuration tab and click Storage in the Hardware panel.
3 Click Add Storage.
4 Select the Disk/LUN storage type and click Next.
5 From the list of LUNs, select the LUN that has a datastore name displayed in the VMFS Label column and
click Next.
The name present in the VMFS Label column indicates that the LUN is a copy that contains a copy of an
existing VMFS datastore.
6 Under Mount Options, select Keep Existing Signature.
7 In the Ready to Complete page, review the datastore configuration information and click Finish.
What to do next
If you later want to resignature the mounted datastore, you must unmount it first.
Unmount Datastores
When you unmount a datastore, it remains intact, but can no longer be seen from the hosts that you specify.
It continues to appear on other hosts, where it remains mounted.
You can unmount only the following types of datastores:
n
NFS datastores
n
VMFS datastore copies mounted without resignaturing
Fibre Channel SAN Configuration Guide
74 VMware, Inc.