When creating an iSCSI LUN on the ReadyDATA you will seen an option to specify the block size for the LUN as shown below:
This is the block size that the ZFS filesystem in the ReadyDATA will use for the LUN. It is important to choose this carefully as it can have implications for performance and disk usage.
You can see that of the 6 block sizes available, there are recommended choices for NTFS and VMFS.
Which ever block size you choose to use, it is important to use the same block size (or larger) when it comes to formatting the overlying file system inside the LUN.
So for example, if we have created a LUN on the ReadyDATA with a block size of 64KB, then on Windows we should choose the same block size when formatting it in NTFS:
The same applies for other filesystems such as VMFS.