To: DownSouth who wrote (11749 ) 12/2/1999 12:57:00 PM From: Greg Hull Read Replies (2) | Respond to of 54805
Sir Galahad, I'd be interested in hearing your reaction (or from anyone else who follows NAS deployment) to a posting by Viangio a couple weeks ago on yahoo:messages.yahoo.com Thank you, Greg _________________________________________________________ NAS comments part 1 by: viangio 11/21/1999 4:46 pm EST Msg: 20668 of 21233 Where do I plugin my new NAS device? On my 100Mbits/sec Ethernet so my clients can reach it. Or, maybe, I'll attach it to my Gigabit Ethernet backbone and my clients will reach it via an IP router that steps up my 100 Mbits/sec LAN to the backbone Gigabit Ethernet. My clients aren't connecting to Gigabit Ethernet or Fibre Channel. My clients are attached to a LAN if in the same company or if they're in the Internet, via DSL, Cable modem etc. So how do they get to their data - via HTTP, CIFS, NFS or NetWare file protocols. And the NAS box understands all of those protocols. The NAS box has a CPU inside and runs an OS of some kind. A lot of the NAS folks are using Linux. They claim it's a low cost specialized kernel for the NAS but actually its just a regular old OS packaged and hidden in firmware. NASes are supposed to be cheap and easy to deploy. All I do is plug it in turn it on and configure it via a Web browser. That's great for some users that can't figure out how to get a regular server running - there are more of them now - small business - home office and file sharing for multiple PCs in a growing % of homes with separate PCs for Dad, Mon and the kids. This is why NASes are becoming popular. There's a market for them now. What happens in the enterprise/Internet None of the databases I know talk HTTP, CIFS, NFS or NetWare protocols to the storage. They read/write blocks. So how do I attach my e-Commerce database backend servers to NAS. I can't. Nor would I want to because transaction performance would go out the window. What do my client workstations do when the NAS box fails? Those little SCSI disks with huge capacity hooked up to a local SCSI bus in the NAS are no longer available to anyone. Folks who tout reliability of NAS compared to regular servers need to think about what OS is running in the NAS box. Most of those NAS devices out there have the same OS as a regular file server and hence the same reliability. How do I backup my NAS box? Over the same LAN wire used by clients to access the embedded OS file server. Where is the tape drive? On the other end of a wire somewhere, attached to another NAS or perhaps a real server? Why would I want to do that when in a SAN I can simply add a third party copy engine to the Fibre and give it direct block access to the data without copies. Why would I lock up my data on those NAS disks when in a SAN any server attached to the SAN and functional in the same zone can see those same blocks. If one server fails clients simply access their data via a path through a different file server. Why wouldn't I want to put my Webserver, Java application server and database server all on the same SAN. This way I can assign disks to servers on demand. With NAS, I only make storage available to client PCs not the middle tier of my Web application engine. The presentation, business logic and data servers. And, those clients are on the other end of an Internet anyway. SANs are an ideal storage architecture for servers - Web servers - Java application servers and databases servers. NAS is a good fit for front ending client PCs. How many of the NAS vendors out there also are talking about backend SANs for all the benefits I just started to describe. There are quite a few of them I can tell you. Go look at the NetWork Appliance architecture. So NAS is simply a gateway to the SAN. It's just an embedded server that's easier to setup for some people. _________________________________________________________