How to reformat datastores on 5.1?

[atariguy]

I'm working on upgrading our hosts from ESXi 4.1 to 5.1. I'm on the first one, and have moved all the VMs to another host. I wanted to delete the datastores and make a new one with all available space using VMFS 5 with the 1 MB blocks. It let me delete all but 1, saying it couldn't remove it because the file system is busy (apparently the host is using it). I upgraded it to VMFS 5 and increased it to fill all available space, but it's still left with 4 MB blocks.

How can I reformat it (or delete and recreate it, whatever works) so that I can take advantage of the new 1 MB block size?

[a_p_]

Is this a local or shared datastore?

Which license/features do you use (e.g. Storage I/O control)?

Does/did any of the VM's have a reference to the datastore (e.g. ISO file location)?

André

[Troy_Clavell]

you'll need to move all VMs to another datastore, not just another host.  Once the datastore is empty, you can delete it.  From there recsans you're storage adapter ensuring all host that had access to the datastore no longer see it and available datastore.  Next, go to the configuration tab and "add storage".  Format as VMFS 5 and you should be set.

Keep in mind only ESXi 5.x can use VMFS 5 LUNs.  So, if you have any non ESXi 5.x Hosts make sure they get upgraded.  Also, ensure your vCenter Server, if using one, is at vCenter 5.x as well.

[atariguy]

It's just a local datastore. We're moving from the free license to  the Essentials license, so we're not doing anything fancy. The VMs are  all gone from the host.

I just put the host in  maintenance mode and rebooted, and it's letting me do what I want now.  Sorry, should have tried that first. Thanks for the helpful suggestions!