I have a lot of friends in the industry who always ask me “How easy is it to get started with virtualization?” Well the answer is, it’s pretty darn simple.
A lot of people get confused with the different products out there, free vs non-free, storage solutions, and also choosing the actual virtualization software they should be using.
Back when I first incorporated my company back in 2006 we had quite a few challenges with our server requirements. We were a fresh startup, had numerous server requirements, but did not want to spend the money on numerous expensive servers. Originally we started out using a custom built server running CentOS and VMware Server 1.x which worked great, but again over time our needs changed.
In 2008, things were getting so busy that I no longer had time to maintain, monitor, and check for hardware failure on our existing CentOS virtualization box and manage updates (for both the OS, and virtualization software). It was time to purchase a real server. Since we purchased a real server, we have upgraded it and modified it over the years. I’m only going to be talking about our current setup since I feel it’s the most secure, and production ready type of environment.
To talk a little about our current setup:
Virtualization Server:
HP ML350 G5 Quad Core Server (dual processor ready)
15GB of RAM (supports up to 32GB)
4 X 146GB 10K SAS SCSI Hot Swap drives (Configured in RAID 5. Server supports 8 drives)
VMware vShere 4 ESXi Software
2 X Ethernet Adapters (Internal LAN, and External WAN)
Storage Server (Custom built):
Intel Quad Core Processor
4GB of Ram
2 X 500GB SATA2 Drives (Mirrored RAID – Configured for Operating System)
5 X 1.5TB SATA2 Drives (RAID 5 – Configured for Storage Partition)
CentOS Linux
Services Configured = iSCSI Target, NFS, SMB
1 X NIC
On our main server we utilize the 4 SAS drives (main datastore in ESXi) for our mission critical data. This includes our domain controller, web server, CRM Server, Exchange Server, file server (business data, and accounting), etc… The SAS drives have very high read/write speeds, along with being configured in RAID 5 provides redundancy in the event of a failure (which hasn’t occurred yet, but we have tested by removing a drive).
Our main server also virtualizes numerous other servers, however most of these are non-mission critical as they are either test environments, or used for product training. We run these virtual machines over a NFS export from our storage box. I/O from the storage box is great over gigabit network and we have not run into any issues thus far.
As you can see, with most of the experience you probably already have with Linux, NFS, and the virtualization concept, it’s actually very easy to setup a worthwhile production environment. But wait! What about the backup?
We used to do offline backups, which became tedious and time consuming as they were done manually. Just recently however we found ghettoVCB, a script for ESXi. We configured this script to do live backups (using snapshots) of our virtual machines to a separate (from above) NFS store on our storage box. Because of the I/O speeds available we can backup all (total of 6) mission critical VMs to a separate server (our storage server) in about an hour. This allows us to have another copy of the VMs on a separate box, which we then later backup onto a large external USB drive (to take offsite).
Also, by having a dedicated storage box when we do require another server to provide virtualization, we would simply map the NFS data stores and be able to access the pool of VMs on the storage server. Of course at this point we would be dedicating a separate network to create a SAN. But until then, things are running great.
Please note that this environment was setup and is currently being used by IT professionals. If your company is looking at virtualizing your environment the free ESXi product may not be for you (depending on available staff resources, software requirements, etc…). Please contact us if you are thinking of implementing virtualization and require assistance!
Until next time!
Stephen Wagner
President