VMFS volume size and VMFS datastore

[vinay1]

I have gone through a book "VMware® Certified Professional on vSphere™ 4 Study Guide" page 148

"A VMFS can have a maximum volume size of 64 TB, but single VMFS datastore can

only be 2 TB. By using a technique known as spanning, multiple extents can be joined

together to form a larger logical volume."

Need a clear explanation on this point with "VMFS volume" and "VMFS datastore".

regards

VINAY

[MauroBonder]

inside of datastore you can extend 32 luns, 32lun*2tb = 64tb

also read this doc, www.vmware.com/pdf/vsphere4/r41/vsp_41_config_max.pdf is very recommended to take vcp

Discussion moved from VMware ESXi 5 to VMware vSphere™ Storage

[vinay1]

Hi Thanks,

A single VMFS datastore can only be 2 TB. means if we are going to create a NFS or iSCSI datastore of size 2TB then what is VMFS volume?

or can u please elaborate with an example/scenario for VMFS datastore and VMFS volume.

[a_p_]

"A VMFS can have a maximum volume size of 64 TB, but single VMFS datastore canonly be 2 TB"

IMO this is a bit confusing, as I can't really see a difference between a VMFS datastore and a VMFS volume.

Actually the maximum supported LUN size for ESXi 4.x is 2TB minus 512 Bytes. This can be used to create a VMFS datastore, which is nothing more than a partition with partition type "FB" and a filesystem "VMFS" (like partition type "07" for "NTFS") By extending the VMFS datastore with additional LUNs you can increase the VMFS datastore to a maximum size of 64TB minus 16kB (32 x 2TB minus 512 Bytes).

With ESXi 5 and its new VMFS-5 version of the filesystem, you can now create 64TB LUNs directly, without the need to use extents.

André