Can’t remove a NFS datastore even though its already offline?

Ran into this tonight, wanted to make a quick post for others who may or may not have seen this before:

This is the message I got after right clicking the NFS datastore and selecting unmount.  Most commonly, this will happen because Vmware thinks a file from the datastore is still being use in by a VM that is running on this host.  Most likely, this is where you kept your ISOs to build your VMs and you forgot to unmount your isos.  Edit the properties of your VMs and make sure there are no mounts still pointing to this datastore.  The easier way to do this would be to use a PowerCLI script, it’ll take care of things like this for you much faster than the GUI.


Building a lab datacenter: Setting up shared storage

In this post, we will setup the initial shared storage.

For this demonstration, I am using an Thecus M3800 with firmware  This was my first NAS purchased about 3 years ago.  At the time I got this, my thinking was hooking it up directly to a TV for movies and such, but those thoughts quickly exited.  While the unit does come with a remote control, what formats it will and wont play is an issue as well as the clunky interface.  It has 3x 1TB drives in it, take care to make sure the drives you intend to use are on the HCL (Hardware compatibility list that most vendors these days have) or you could end up with interesting and unexpected results.

Here is our basic interface:

From here I am going to destroy the current raid on the system and recreate it since this is  now the oldest of my NAS’s and is being repurposed for this.  After clicking ‘Remove’ above, we get this:

Raid destroyed.

Now we go back to the raid interface and must select the raid type and stripe size:

I selected a stripe size of 4k and raid 5.  Here is the build time for this specific system.  This will vary depending on the stripe size, raid 5, the size of your hard drives, and your nas system.  Expect it to take a while.  Later I will have a demo of this on a NetApp system.

The raid build is complete, as we are using raid5, we lose 1 disk for parity.

Since our intention is to use VMware, we need to add a NFS share.  With VMware you can have LUN (block storage that use iScsi or Fiber Channel) or NAS storage that supports NFS only (no CIFS).  This Thecus does not support iSCSI, therefore we will be creating 2 NFS shares on it, 1 for virtual machines and a different share for data.

After the share is created, we have to add nfs permissions for VMware to be able to mount the share.  This is like any other NFS share.  VMware ESXi requires root= access as well.  Here we are saying the host is allowed to mount the share with read/write and root access.

Another share was created as ‘data1’ with similar permissions.

The storage is now set up.  In a future post, I will walk through the installation of ESXi 5.