August 8, 2005 at 3:15 pm
Here's the situation...
We're implementing a SAN and want to consolidate from 6 SQL Servers to 3. We do NOT want to do clustering for now.
The original 6 SQL Server instances were installed as 'default', one instance per SQL Server. Because of usage differences we want to install multiple instances on 1 SQL Server. The original SQL Server boxes are addressed via an Alias (not the Windows server name).
What we would like to do is; install multiple intances on one box but let the connection to the boxes be the same as they were before. For that we would have to have two NICs and assign a different IP address to each, but still have each instance listening in on port 1433. We're trying to avoid having to change all our custom programs' connection strings. Doing so would set back the project a month or so.
Can this be done?
August 9, 2005 at 2:31 am
IMHO, I think you're making it hard for yourself, but I'll try and give you some ideas.
Multiple instances (6 of them on 1 box or 2 per server, 3 server) will run like a dog, regardless of usage differences. I/O and RAM contention. CPU contention. Let a single instance decide how it allocates resources - it's easier. Even with 8 CPU, 8Gb RAM, you have to carve up the resources somehow. That is assuming you have OS and SQL enterpise/advanced editions...
Only one instance on the box can use port 1433. Period. Regardless of NIC count.
If the original boxes were addressed by an alias, just change the client aliases to point to the new box, the clients still use the alias. You can specify a port in an alias, but it may (I never seen this setup) be overridden by the connex string so if you have specfied port 1433 (in your connex string) on top of the alias then you may have problems.
How customised are your connex strings? For info, how far can they be customised? Are they hard coded within your app?
Can you use DNS CNAME entries to dummy up 6 SQL Servers pointing to an actual hostname? This is a single point solution rather that change all your clients.
My choice would be all dbs on one box, DNS entries, no aliases, connex strings in xml or .ini file.
Cheers, Shawn
Viewing 2 posts - 1 through 1 (of 1 total)
You must be logged in to reply to this topic. Login to reply