Storagedesign question - Filepartitions bigger than 2 TB on a VM-host

Hello,

I've an question regarding storagedesign. We have a VNX5300 connected to a VMware-ESX-farm, 99% of our servers are VM-hosts.

The VMware-farm has several datastores which are 2 TB. We have several servers that have filepartitions which are tipping that limit of 2 TB.

I can create disks larger than 2 TB. Technically that no problem, but..... I have to use RDM to get over the VMware's limit of datastores. Even more, If I create disks, larges than 1,5 TB, I run into problems with my backupwindows and RTO/RPO. I will not meet the RPO and RTO.

The customer wants something like a neverendig disk. It must be able to grow, without the user noticing any changes.

In my opinion I have different options:

1) Create multiple disks at VMware-level and tie them together at Windows Level.

     Pro: Disk will grow with the user see anything changes

     Cons: less flexible with storage vmotions and. Not meeting my RTO/RPO

2) Create RDM's bigger than 2TB and let it grow.

     Pro: The user will not see any difference and the disk can grow

     Cons: Worry about RTO and RPO at backuplevel.

3) Create multiple disks at VMware-Level and use MS Windows Mountpoints

     Pro: can uphold my polciy regarding Datastores and disks

     Cons: My folder-structure will be higher math and administration

4) Create multiple disks at VMware-Level and use MS Windows DFS.

     Pro: Flexible with storage-vmotions and Backups to meet my RTO/RPO

     Cons: Lot of overhead for every 1,5 TB disk I need an new Server. Still the folderstructure is higher math and a lot of administration.

I've asked my colleages the same question, but I'm curious to find out your opinion How to address this design-challenge.

Kind regards,

Antoine Schokker