dagkl
Contributor
Contributor

getting limit of 256GB when trying to add a virtual disk

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I am using a local Adaptec 3405 Sata RAID card. The card presents disk as LUN to the ESX. I add a datastore that is as big as this disk. When I am trying to add a virtual disk the size of the datastore I get an error message saying that I am out of range and sets the disk size to 256GB.

This is starting to get really annoying. I tried to use the entire disk with raw device mapping.I get the error that my LUN is not a physical disk or it des not exist. Could this be because it is a RAID disk?

I have given that up, and wanted to add a big virtual disk instead, when this happens. Spanning two disks in windows is not an option.

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Dave_Mishchenko
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The maximum size of a VMDK file is controlled by the block size of the VMFS partition. You'll have to reformate the partion and select a block size of 2 MB , 4 MB or 8 MB.

Block size - maximum VMDK size

1 MB (default) - 256 GB

2 MB - 512 GB

4 MB - 1024 GB

8 MB - 2048 GB

To use a local storage LUN as an RDM you have to add it as a generic SCSI device instead of a RDM.

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Dave_Mishchenko
Immortal
Immortal

The maximum size of a VMDK file is controlled by the block size of the VMFS partition. You'll have to reformate the partion and select a block size of 2 MB , 4 MB or 8 MB.

Block size - maximum VMDK size

1 MB (default) - 256 GB

2 MB - 512 GB

4 MB - 1024 GB

8 MB - 2048 GB

To use a local storage LUN as an RDM you have to add it as a generic SCSI device instead of a RDM.

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dagkl
Contributor
Contributor

Thank you very much, I will try to reformat it.

How do I add it as generic scsi instead of RDM?

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kjb007
Immortal
Immortal

You won't need to assign a generic device if you reformat and update the block size. If you have space left over at the end of your disk that is not in a datastore, then you can create a partition out of it. Then go to edit settings of a vm, and add a device, and add scsi device. This should allow you to select the new partition to the vm.

-KjB

vExpert/VCP/VCAP vmwise.com / @vmwise -KjB
Dave_Mishchenko
Immortal
Immortal

Here's a thread that discusses a local SCSI LUN as a RDM. Unless you specifically need it, I would stick with VMFS partitions - http://communities.vmware.com/thread/145589?tstart=0&start=0.

dagkl
Contributor
Contributor

Thank you, I will go for the virtual disk. It is 500GB now.

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