Storage is my bread and butter. I cut my teeth on fine storage arrays from EMC. Since then I have moved on to many different vendors and I have learned one truth: storage can be hard or simple. VMware can make storage easy. I am very excited about SDS (software defined storage) I personally love VSAN and Nutanix they are the commercial solution to something google figured out long ago. Storage is simple but storage arrays are hard. VMware has been making great strides to simply storage but I find lots of people are afraid to use them. They prefer to stick non-flexable arrays and provisioning methods. Please don’t get me wrong these designs are required for some solutions. Some transnational processing requires insane IOP’s or low latency. This design is for the rest of you.
You have a VMware cluster with highly available shared storage. You have a mixed VMware cluster running lots of different applications. Some of your virtual machines have lots of drives spread all over your storage luns. Some of your virtual machines have 2TB drives attached so you have standardized on 4TB lun’s for all VMFS datastores. All of your luns are thin provisioned. You need to provide a solution that is easy to manage but avoids lun’s running out of disk space in the middle of the night. You are also concerned about performance you would love an automated way to move virtual machines if I/O on a lun is a problem.
The following assumptions have been made:
- You have enterprise plus licensing
- You are running 5.5 and all VMFS luns are at least 5.XX format native
- You do not have an array that provides auto tiering
- You do not need to take into account path selection in the process or physical array
VMware’s Storage cluster provides for all the requirements and needs. By using all storage in a storage cluster management of storage becomes easy. Just group storage together based on IO metrics (do not mix 15,000 disks with 7,200 k disks) into a pool or datastore cluster. Enable storage DRS and your life just got a lot easier. Enable automated storage DRS for ease of management. This will help you place new virtual machine and move virtual machines off luns that are above a certain threshold (80%) by default. Now you just need to enable IO latency moves. This will move virtual machines to other datastores if the latency on the datastore passes a threshold (default 10ms) for a specific duration. I have used storage DRS just like this with over 2,000,000 successful storage moves without a single outage.
Abstract storage -> Pool -> Automate
All are provided by this design.