akoustic
Contributor
Contributor

.vmdk is larger than the maximum size supported by datastore

Hi

I'm trying to create a new VM using RDM. I have selected Raw Device Mapping at "Selet a disk" part of the "Create a new virtual machine" and I select 50GB iSCSI disk that was presented using IPStor.

The problem I have is that it keeps complaining that the .vmdk is larger than the maximum size supported by datastore. I don't get this as I have the block size as 1MB and it should be good for 256GB?

Am I missing something?

Thank you!

Kevin

0 Kudos
6 Replies
jsykora
Enthusiast
Enthusiast

How much space is available on the primary datastore where this VM's .vmx file is located? When you create an RDM it will place a RDM mapping file in the primary VMFS Datastore where the .vmx file is located. I believe with vSphere there is some admission control calculation that takes place for the primary datastore to ensure that there would be enough free space on the datastore if a snapshot were taken.

0 Kudos
akoustic
Contributor
Contributor

I have about 250GB of free space in the datastore. I thought this would be plenty of space.

0 Kudos
kjb007
Immortal
Immortal

Can you double check the presentation of the raw device? Make sure it is 50 GB in size, and is reporting correctly.

vExpert

VMware Communities Moderator

vmwise.com / @vmwise

-KjB

vExpert/VCP/VCAP vmwise.com / @vmwise -KjB
0 Kudos
rickardnobel
Champion
Champion

I'm trying to create a new VM using RDM. I have selected Raw Device Mapping at "Selet a disk" part of the "Create a new virtual machine" and I select 50GB iSCSI disk that was presented using IPStor.

The problem I have is that it keeps complaining that the .vmdk is larger than the maximum size supported by datastore. I don't get this as I have the block size as 1MB and it should be good for 256GB?

There must be some confusion here. The block size you mention is for the VMFS file system, but you are trying to create a Raw Device Mapping, that is a direct access LUN for a VM and that LUN should not have VMFS and by that not any block size.

The vmdk file should only be about 1K or similar, and contains mostly the pointer to the raw LUN.

My VMware blog: www.rickardnobel.se
0 Kudos
akoustic
Contributor
Contributor

You are right. That should be the case however, everytime I create a new vm with disk pointing to RDM it will generate the error message.

I don't know what step I would have missed that would forbid me.

Thanks,

Kevin

0 Kudos
a_p_
Leadership
Leadership

Kevin,

since what you are trying to do usually works, I could think of a compatibility issue.

Did you already check the VMware HCL, whether the IPStor firmware you are using is supported for the version of ESX/ESXi you have?

André

0 Kudos