Has anyone utilized something aside from a SAN to run their VMWare images off? We are looking to drop in two HP Servers and VMWare on them and run them off a SAN. Due to the cost of SAN though our CFO and VP are wondering if there are any viable alternatives (I.e. NAS) that can effectively run a VMWare. I can't think of any off of the top of my head. IF anyone can provide one or a good article outlining why to stick to SAN that'd be great.
Just use the vSA
I run a couple of virtual machines stored via NFS to a FreeNAS server and everything goes OK. You could use snapshots or HA independent from the VMWare Server.
You are not making yourself totally clear. What do you mean by SAN (storage area network)? Fiber channel SAN? Then yes you are on the expensive side. What do you mean by NAS? Copper based ethernet storage? Also, NFS would require some storage server somewhere with an NFS server running. Not far different from a dedicated NAS.
Then why not do what we have done. Our storage elements are off the shelf systems with plenty of storage slots (ex. DELL R510). Installed CentOS (or your flavor of Linux), made it a iSCSI host. Ditch VMWare and run CentOS/KVM on your VM hosts attaching iSCSI devices on them using a good quality copper ethernet switch. Of course, depending on your budget/applications you can mix and match some of these. You could also start small and grow into fault tolerant systems (dual storage systems, several VMhosts etc etc).
It really depends on what level of performance and reliability you are trying to achieve. ESXi can happily run VMs using iSCSI or NFS, so any system which can expose its storage using one of these protocols will do.
You can build a SAN on almost anything, the issues are reliability, stability, performance, support, and cost.
My suggestion would be to purchase reliable hardware (think server class) with a hardware RAID controller, purchase disks to meet your performance and capacity requirements, and use something like Open-E (DSS V6 Lite) or openfiler to create iSCSI targets for your VMware hosts.
I run an iSCSI SAN at home on a Dell Inspiron 545 workstation. I'm not saying that's what you should do, but I am saying that the options are almost limitless, constrained only by your budget and needs.
VMWare runs perfectly happily on an NFS share. You don't absolutely need block storage (a SAN) to get all the storage-based features like vmotion and stuff. Any NFS share running a supported version of NFS will do, so that opens you up to anything from a homegrown NAS to a dedicated hardware NAS.