i copied this from some other blog:
So there I was, trying to create an uber sized partition on my RAID 10 array within my vmfs3 partition.
The problem? A general system error occurred: The file is too big for the filesystem
This was the error I received when attempting to create a 600GB Virtual Disk on VMWare ESX Server 3.5.
This was a problem. I learned the reason why though. Since I partitioned the storage volumes during installation the installer used block size 1 which only allows Virtual Disks of 256GB.
The solution? Reformat the volume with larger block sizes.
Block size Max Virtual Disk size
1 256 GB
2 512 GB
4 1024 GB
8 2048 GB
Now I had to figure out how to do this without destroying my data.
My server has a 73GB Mirrored boot drive and 900GB of RAID 10. Fortunatly I had enough free space on the boot drive to transfer the data from the RAID 10 temporarily.
Logging into the console of the host I:
Having previously taken note of the volume label and the device name of the volume I wished to modify, in my case vh-01:storage1 and vmhba1:1:0:1, I move the existing data out of Storage1 and into Storage2.
Use the Storage Browser to move your VMs
Next I ran the command to reformat Storage2
vmkfstools –createfs vmfs3 –blocksize 4M -S vh-01:storage1 vmhba1:1:0:1
I chose a 4MB blocksize because this volume will never exceed 1024MB.
Then I just moved the data back to Storage1.
Filed under: vmware