Hi All,
I have been in the process of building a Linux Cluster in a Vsphere utilizing SuSE's HAE product. This utilizes Pacemaker/Corosync for clustering resources. The main purpose is to build a File Server that use NFS to export files. The file server is on the smaller scale but would like the ability to scale out in terms of storage & performance if requirements change.
So far I've looked into DRBD and OCFS2 and built some test instances within these clusters, but found some limitations to our requirements mainly around snapshotting VMs. I've also looked into using VMware's Fault Tolerance in HA Mode and again found some limitations as well. So I am hoping someone could suggest something that perhaps I've missed? Are there any other options I am not considering?
So here's the requirements we are trying to satisfy
Requirement:
- A Linux based NFS server
- Seamless redundancy between 2 VM’s
- Ability to provide High Availability over 2 ESXi Hosts.
- Ability to create snapshots for VMs
- Ability to do VDP backups
- Ability to support 2 CPUs (1 CPU may not be scalable)
- Storage capacity of approx. 150-200 GB for Data & 20 GB for OS
Option 1: 2 x SuSE in Linux HA Cluster (w/ OCFS2) VM’s w/ RDM mapping
- This was the option we were currently working with where we create an RDM to our SAN and share that mapping across multiple VM’s over 2 ESXi hosts
- Limitations:
- Cannot backup any data nor do snapshots because of RDM
- Cannot do snapshots of the OS disk because the VMs live on 2 different ESXi hosts and will require the Bus Sharing to be set to Physical to share the RDM across multiple VMs
- Only way to make this work is to sacrifice HA by putting all VM's on a single host.
Option 2: 2 x SuSE in Linux HA Cluster (w/ DRBD) using Data stores
- All drives use their own Data Stores, but there is a shared disk to support STONITH. The Bus Sharing for that one controller is in physical
mode. - Limitations:
- Old technology
- Inability to scale well
- Novell support requires a STONITH device to be enabled such as a shared disk to receive support for their HA product. Therefore we are stuck with a shared disk in physical mode to have Availability across multiple ESXi hosts.
Option 3: ESXi HA Cluster using Fault Tolerance
- A single VM with Linux and enable Fault Tolerance option. Fault Tolerance would create an identical VM to provide redundancy and would continue to run seamlessly if the first VM ever lost its
connection.
- Limitations
- Requires 3 ESXi Hosts in HA Cluster mode
- Cannot take snapshots
- Fault Tolerance currently does not support more than 1 CPU
Thank you,
Jason