Virtualizing storage
24 Jul 2006 - DaveI have to be careful here, the whole virtualizing thing is getting to be like a hammer turning everything into nails…
But virtualized storage has been mainstream for longer than virtual machines (ie VMware, Virtual Server). It answers the question, “what do you do when the harddrive in your server fills up?”
You can only add so many drives to that server.
It gets pretty complicated to find stuff after awhile.
The simpler solution is a NAS (Network Attached Storage) which is a lightweight server with lots of disk space connected directly to the network. They come mainly comes as rack mount appliances that you plug in, configure and more or less forget. It shows up as a mappable network drive or share. Many vendors sell these appliances (HP, Dell, IBM, EMC).
There is also software so you can roll your own NAS. FreeNAS is an example of the software NAS solutions. Robin Harris is a Storage Guru with many years experience supporting storage needs. He has an interesting article on FreeNAS where he published test that he ran using the software. His findings will probably make vendors selling more expensive solutions very nervous. His article on White Box Arrays will really make them worry!
The bigger, more complicated solution is a SAN (Storage Area Network). A SAN using involves some very expensive hardware and the need for experts to setup and manage. For the price you get better performance and more seamless integration. While a NAS appears as a shared network resource, a SAN appears as an actual harddrive.
There are software solutions so you can roll your own SAN as well. iSCSI Enterprise Target is an example.
By moving your storage out of the server you can grow it more easily when needed. There are other advantages but that’s the big one.
The two Open Source solutions mentioned here can provide a decent introduction into the technology and keep to a budget.