Multiple Instances of SQL on the same server? - Opinions Please
-
Hello,
We have a mission critical SQL application that currently uses a SQL 7.0 Server. We are about to perform an upgrade and SQL 2000 has become a MTR. I would like to spare my budget yet another $10,000 hit ($5,000 per processor) for SQL licensing so I have been considering placing these DB's on another SQL Server I have that is already at the 2000 level.
This other server was purchased for us to grow into so it has GOBS of hardware resource availablity. My only concern is that we may experience a problem with SQL Services and be forced to restart them - which would affect our mission critial app.
Therefore, I have been considering installing another SQL instance on this server and placing the critical DB's there. This will give me a separate set of services, etc. Correct?
Anyway, I am looking for information on running multiple instances - performance, stability, etc.
Thanks in advance.
Ryan Hunt
-
Well, I have implemented the mulptiple instance envirment arround one month back.Upto now it didn't cause any issue.
My Blog:
http://dineshasanka.spaces.live.com/ -
Bear in mind that if you run the Standard Edition, you still have to buy a license. If you use Enterprise Edition, you can have as many instances as possible.
--------------------
Colt 45 - the original point and click interface
-
Our SQL Server here runs multiple instances without any problems. Just bare in mind a good amount of memory and maybe some mem tuning for each of the instance and you will be ok. And you are on a machine that can be scaled up if you need to. Go for it.
-
They've clarified the position on processor licensing. If you're doing per processor and not per server, you can run as many instances as you want so long as the processors they are running on are licensed. That's a change from what I thought, too, because I was under the same impression you were, Phill.
Microsoft SQL Server how to Buy FAQ
Relevant Excerpt:
Q. How does licensing work with the multi-instance feature in SQL Server 2000?
A. You can run multiple instances of SQL Server 2000 on a single computer. Multiple instances are used by organizations that have several applications running on a server, but want them to run in isolation so that any problem in one instance will not affect the other instances.
Under the Processor licensing model of SQL Server 2000, you can install multiple instances of SQL Server on the same computer without having additional licenses. Under the Server/CAL model, you can install multiple instances of SQL Server on the same computer only if you use SQL Server 2000 Enterprise Edition. With Standard Edition, using the Server/CAL licensing model, you must have a separate license for each instance.
K. Brian Kelley
@kbriankelley -
That's good news. This server is licensed by the processor (dual). So, I have a question about memory. SQL 2000 standard is only able to recognize 2GB of memory. Does that mean that each instance can claim their own 2GB? This box has 4GB of memory.
Memorywise, what I was thinking is this:
1) The current installation - left memory settings unconfigured - should default to 2GB.
2) Additional mission critical installation - configure memory to 1GB (the SQL reliance of our mission critical app is not transaction heavy - it houses system tables). Our business data is on an AS400.
3) Leave 1GB for system use.
Thoughts?
-
Interesting topic. We are on the same one here at work except we are throughing active/active clusters into the mix.
Even though noone is seeing problems it doesn't mean that one instance will not effect another instance. They become two applications running on the same server, same cpu's, same memory, same nic cards, same disks, etc.... If one instance puts a bottleneck in any of the hardware the other instance will suffer too.
"Keep Your Stick On the Ice" ..Red Green -
Brian, that was a relatively recent ( 6 to 12 mth) change in licensing. I'm glad you found the specifics, I had only heard comments from MS.
Multiple instances run just fine, have some extra memory on the box, and give the important one more. I would attempt to isolate the DASD (separate partitions) for the main instance also. Don't want someone on the other instance running something that consumes all the free dasd and shuts everyone down.
One issue, earlier clients (can't remember the details) cannot use the named instance concept. There are a couple of ways around it, I believe an alias will work, or upgrade the client.
KlK
Viewing 8 posts - 1 through 7 (of 7 total)
You must be logged in to reply to this topic. Login to reply