Questions on VMFS Blcok Size?

[TonyJK]

We would like to know

1) Is it possible for us to find out the block size used for a VMFS volume in VI Client GUI ? If not, which command can be used to find it out ?

2) For 1 MB Block Size, the maximum VMDK file is 256GB. Does it mean that we can create a VM up to 256GB maximum ?

Thanks

[Dave_Mishchenko]

If you look at Configuration \ Storage and select the datastore, the block size will be listed. With a 1 MB block size, the maximum VMDK would be 256 GB, but you could create a VM with multiple VMDK file. If you need a single VMDK larger than 256 GB then you would need to format the partition with a larger block size.

[rpartmann · Accepted solution]

Hi,

in your vi client go to your server/configuration/storage/

click on a datastore name and you will get additional info underneath the datastore list

vmfs version and block size

ad 2)

VMFS3

blocksize max file size

1MB 256GB

2MB 512GB

4MB 1 TB

8MB 2 TB

hth,

Reinhard.

ps: Award points if you find answers helpful. Thanks.

[TomHowarth]

Tony

Block size controls the maximum size of a VMDK

1MB = 256MB

2MB = 512MB

4MB = 1024MB

8MB = 2048MB

this means that the maximum size of a VMDK in a 1MB block formatted VMFS partition will be 256GB, however if you have the space in the partiion you can create multiple 256GB VMDK's, this is the case with 2MB and 4MB formated partions, as 2048GB is the maximum size of a VMFS partition (without Extents - for those who will pick this up) only a single 2048MB VMDK can be created in a 8MB formatted partition

Tom Howarth

VMware Communities User Moderator