SAN Implementation

[smiley77]

Anyone out there ever connect a web farm environment to a SAN? What I would like to do is upload web changes to one location on the SAN and configure IIS on each of the web servers on a virtual server to connect to the one location on the SAN. The farm would be load balanced.

Ex
WEB01, WEB02, WEB03
\ | /
D:\Inetpub\WWWRoot\SiteA --- > SAN 01


This would make deployments easy on a web farm if possible

 

[TheKub]

Originally posted by: smiley77
configure IIS on each of the web servers on a virtual server to connect to the one location on the SAN.

Can you clarify that bit. By Virtual Server do you mean a host machine (physical box) or a actual virtual server (1s and 0s).

I'm a bit confused because its plural web servers but singular virtual server but you want multiple connections to the san.

 

[smiley77]

I sure can clarify... I have a host virtual machine[HOST01] with virtual slices [WEB01,WEB02, WEB03] each have Windows Server 2003 installed. I would like these 3 slices to be part of a Web Farm that connect to one SAN device via a fiber connection. Now I do not want to create separate disk partitions for each of these slices, but only a single partition on the SAN that all 3 slices can see. This would allow me to upload web files to one location and have each node of the web farm see the changes without replication. Now I assume I would setup a cluster for WEB01, 02, and 03...however, I am uncertain if it is possible to see the one disk partition. I have never setup a cluster before, but if I am not mistaken is uses a single drive amongst all nodes anyway, right? I just need to know that what I am trying to accomplish is possible. Thanks.

 

[TheKub]

I can't offer alot of certainty but what I do know is that its is not an issue to create a LUN on the SAN that all 3 servers can see.

What I am not sure of is can all 3 can see the same virtual disk at the same time. You create virtual HDDs on the LUN, now the virtuals can access the same LUN but not necessarily the same virtual disk (not sure if there is locking or not). In VMWare its this feature that allows for VMotion (not sure if it hands off the lock or whatnot). I see what you are trying to do with the speedy rollout of updates but even if you can do what you want Im not sure its a good idea. All three servers will be using the same location on the SAN and might tax the IO on it.

 

[smiley77]

Kub,

Thanks for the responses. That also was a concern of mine. I believe with Clustering Services, the nodes in a server see the same Quorum disk on a shared storage, so that one one node fails the other nodes become Active. I was hoping the same may apply with additional storage location on the SAN and therefore the nodes would fail over. I wondered how the load balancing would work across multiple nodes accessing the same virtual disk at the same time. I mean, there will be multiple sites competing for access to the virtual disk and thus could cause an access issue. However, I've been told that SANs have amazing caching capabilities and I wasn't sure how that would play into this. The SAN is an EVA8100. I am by no means a SAN guru and have never worked with one before. I am simply a DBA with a hosting background looking to improve our web and sql environments.