I've heard a lot of about NAS (network attached storage) and how it can cure large storage needs. Anyone here know anything about it and does anyone know how it can benefit those in the hosting business? Is it possible that some hosting companies out there are using SAN for shared hosting? Thanks...

Can't tell for sure but you seem to be using NAS and SAN interchangeably. They are very different things. We looked at using a SAN for hosting but found it cost prohibitive. NAS is generally cheaper but performance is much less. I believe Hostopia uses a SAN, datapeer as well.

I consider SAN and NAS storage technologies my area of expertise. I've been working with SAN and NAS for the last 3 to 4 years and hold storage certifications from Compaq and EMC.

First off SAN and NAS as mentioned above are 2 very different things.

NAS = Network Attached Storage.
Does the hosting business use NAS? You bet! Do you have a server that is basically a file server to your other key servers? If so, then you already have a NAS solution even if you didn't know to call it that. You may see offerings from EMC and Compaq (which are the key players in the NAS storage market) labeled as a NAS storage solution. Compaqs NAS solution is nothing more than one of their proliant servers running a customized version of Win2k with a whole bunch of disk arrays that enable hardware raid. They also have a couple of network connections in the box, either 10/100 or gig-e. Their software is where you get the benefit of buying the product. Some features of their software include things like snapshot, serverless backup, storage management, etc..

SAN = Storage Area Network
Does the hosting business use SAN? You bet!
Someone mentioned cost above.. within the last year or so, storage has gotten even cheaper, including SAN storage. What makes it more expensive than say NAS? SAN is basically a totally different data network than your regular cat5 10/100 network, meaning that all the data moving around on the SAN doesn't affect your cat5 10/100 networks speed. There are ways to make a NAS solution on a different subnet or use different cables, like a "red-net" type of solution, but then your cost gets up to where you should look into a SAN solution. SAN uses SCSI over fiber channel protocol on fibre cable. Thus the speed is going to be superb compared to NAS. Industry now has 1GB/s and 2GB/s HBA's (Host Bus Adapters). HBA's are basically like a fibre network card with the differences being in the hardware to use fibre channel protocol (since it has its own layers, etc..). You connect the HBA's from your servers into a switch (just like a typical network switch, except it talks fibre channel), and from the switch it connects into the storage array. The storage arrays usually have a whole bunch of cool software that automates and eases management of the storage. Backup is also where I've seen some really cool stuff done.

Sorry, didn't mean to teach a class or something, but thought this info might be useful..

If anyone has any other questions about NAS and SAN, I'd be happy to answer them for you.

laterz,
raqworld

raqworld, thanks for the great info/intro

Peter

I bought an 80GB External Hard Drive from Staples (don't say anything..I had money, I was there..I didn't care about saving $20 from buying it online :))..but it's super nice.

All you do is plug it in..assigns it a drive letter automatically - all USB..would be great for connecting to a server at a datacenter and just backing your sites onto it (and of course having a backup at the office..)

Your most welcome Peter!

raqworld

raqworld, thanks for the info.

I have some more questions here.

1) If i were to use SAN technology for hosting multiple sites (thousands), doesn't that affect the performance of the SAN server?

2) Does having multiple WWW servers with load balancers connected to the SAN backend help tackle the problem?

anyone care to have a go? thanks...

Originally posted by m00ds
1) If i were to use SAN technology for hosting multiple sites (thousands), doesn't that affect the performance of the SAN server?

2) Does having multiple WWW servers with load balancers connected to the SAN backend help tackle the problem?


1- If you were using 1 server to do this, then yes, I would say it would affect your performance. For that many sites, I would (and most here) would probably recommend multiple servers for better performance..

2- Absolutely! The SAN technology is awesome when it comes to load balancing and fault tolerant (ie: cluster) solutions. Thats the value of shared storage- one system fails, the other takes over the storage and keeps on going (or helps out in load balancing)..

If you would like to discuss more about the technologies out there, let me know what type of solutions your looking at. :)

laterz,
raqworld