Cannot create VMFS Datastore on newly installed ESX 6.5 (Licensed)

[ESX_STAGE]

Hi,

we have a new Dell PowerEdge R730xd server setup and preconfigured with DellEMC Customized Image ESXi 6.5 Update 1 A08 (based on ESXi VMKernel Release Build 7388607) .

I am using VSphere Essentials License.

Without any changes, I logged into the Vsphere Web Interface /ui/#/host and attempted to create a new VMFS datastore but got an error:

Failed to create VMFS datastore test - Cannot change the host configuration.

SPECS Used:

Name: Test

Devices: 1 x 10TB Virtual Disk (Raid 10 x 4 Physical Disks) setup by Dell.

Size to create VMFS datastore: 1 TB

VMFS Type:  Both VMFS 5 and 6 failed in separate tests.

No other existing datastores or VM's.

Contacted Dell but awaiting response and as it ESX they may not help.

As we need this server setup ASAP I was wondering if anyone knows of any resolutions or a point in the right direction with this.

I have used ESX different flavors for years and never seen this before.

Any help or suggestions greatly appreciated.

I also have limited command line experience.

[Mallenge]

Hey, everybody! I figured out the problem with my home lab, at least. Could be worth a look to yours, as well. 

My main problem was with the iSCS communication between the hosts and the FreeNAS. I was continuously getting timeout errors between them and when I reduced the MTU from 9000 to standard 1500, the timeouts stopped and the volumes were correctly created without issues. 

Therefore, my tip is just this: check the protocols with the communication between the hosts and the storage. 

[zachmi23]

I can't believe it, but this worked for me! I went into each VMKernel Adapter and sure enough, the iSCSI adapters had an MTU of 9000 (presumably to allow for jumbo packets) so I changed them to 1500 and the datastore created without issue!! Cheers!!

[PaulRobert1]

Hello, Thank you very much Cookies04, your procedure worked like a charm.

[Crunchy-Nugget]

@Cookies04 Thank you. This helped. My disks were taken from another device that had a RAID controller. The disks were initialized with the RAID controller prior to removal to erase them, but I guess it doesn't work.

[aamirgondal]

hi, I want to ask have you resolve your issue?

i am having the same problem

thanks

[Mallenge]

Hello! Yes, I have. Take a look at my post on this same thread about the MTU and this has a big chance of solving your problem. 

[davdjross]

Thanks for this!

I'd just updated my homelab with a 2.5gbe switch and stupidly assumed 9000MTU would be what should be set at rather than 1500. Clearly not. Set it back to 1500MTU and the datastore was created immediately.

[m_manar]

Thank you !!!!!!!!

[m_manar]

@Cookies04 i logged in only to say: thank you! 

[Mattneed]

@Cookies04 I know this is old as hell but even in 2022 you the MVP thanks for this!!!