ESX 3.5 Local Storage Block Size

One limitation of the default install of ESX 3.5 is that the local VMFS storage gets formatted with 1Mb Blocks.  So what do you do if you want to store servers on local disk storage and want a virtual disk larger then 256GB?  ESX 4.x changes things a bit, but for 3.5 here is how to fix that.

vmkfstools --createfs vmfs3 --blocksize 8M vmhbaA:T:L:P

1. Move any virtual machines off to other storage.  (NFS, iSCSI, or somewhere else)
2. Logon to the console as root
3. Execute the vmkfstools command, this will reformat the partition with the block size specified (2M, 4M, 8M) and without a volume label.
4. Logon to the VI Client
5. Select the host, configuration tab, storage, and refresh.
6. Find the local storage with the UID number, and rename it to a logical name.
7. Move virtual machines back to local disk.

Additional Ref: how-to-change-the-blocksize-of-a-vmfs-filesystem

For ESX 4.x take a look at this KB from VMWare.  KB Article: 1012683