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Can you help me with my software licensing question?

I'm tempted to use a DR server which holds a mirrored copy of a database to also perform test restores and integrity checks of the principle database.

There maybe issues with network bandwidth (copying the backup from the primary server along with the mirrored traffic) and CPU capacity on the secondary DR server (performing redo and running checkdb on Standard edition), besides these, if I do restore and recover the primary database on the seondary DR server, will I have to license the box?

I wouldn't be using this copy of the primary database for anything other than running checkdb (honest guv).

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marked as duplicate by Skyhawk, Mark Henderson Nov 14 '11 at 5:19

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

Had another thought. The architecture includes a virtual machine acting as a Witness server which is housed in the same data center as the Primary. It's licensed as Standard Edition and has only a single processor. Will have to check how much hard-drive space is available - but may be able to restore backup of the Principle database across the network from the primary and use the Witness for integrity checking. I assume this wouldn't cause any licensing issues or impact on its role of being a Witness. – SuperCoolMoss Jun 28 '09 at 17:21
up vote 4 down vote accepted

Express or Developer editions won't do it as you're already using mirroring.

Basically as soon as you use the instance for anything apart from hosting redundant copies of databases through log-shipping or mirroring, you must buy a license.

It's a bit sucky as most people would expect that testing restore sequences and running consistency checks would be ok, but them's the rules!

If you go this route, be careful how you place the databases, in terms of I/O subsystem - the extra I/O load from CHECKDB (usually way more than doing a restore) could make your mirroring REDO queue grow and contribute to a slower failover.

Hope this helps!

PS I had an idea - what you could do is log-ship to the same instance the database that you're interested in - then you will be testing the log backups at least. Technically, restoring using WITH STANDBY and running CHECKDB is against the licensing model too...

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Can't I add an additional named instance (Developer) to the secondary for this purpose and buy a cheap single developer license? – SuperCoolMoss Jun 27 '09 at 20:07
No - you're not allowed to use Developer licensed instances in production like that - you're basically using it as a Standard or Enterprise instance. It's a big gray area, but technically you're not allowed to. – Paul Randal Jun 27 '09 at 20:46
OK. Shame really, as it would have been good usage of redundant hardware. – SuperCoolMoss Jun 27 '09 at 20:59
I know - that's the quandary that people have, especially when considering cap-ex for a redundant system. It does seem daft to me that doing something like restores and CHECKDBs isn't permitted. Hmm - an idea - I edited my answer. – Paul Randal Jun 27 '09 at 21:43
Hmmm... I've had an idea also - what if I restore the database to the secondary as model and run checkdb against that. Hmmm... lawyer time! – SuperCoolMoss Jun 27 '09 at 22:35

I've always been under the impression that a 'passive server' is allowed for DR to log ship or mirror to. From microsoft:

When doing failover support, a server is designated as the passive server. The purpose of the passive server is to absorb the data and information held in another server that fails. A passive server does not need a license if the number of processors in the passive server is equal to or less than the number of processors in the active server. The passive server can take the duties of the active server for 30 days. Afterwards, it must be licensed accordingly.

You still need to buy an OS license though.

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Hi Nick, unfortunately you can't restore databases for the purpose of testing / integrity checking on a passive server with affecting the licensing model. – SuperCoolMoss Jun 29 '09 at 20:38
Does technet cover you for this then? – Nick Kavadias Jun 30 '09 at 1:07

If SQL Express won't cut it for what you're trying to do the at the very least you'll need a SQL Developer Edition license. You might be in some gray area with even a SQL Developer license depending on what you're doing with that mirrored copy.

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Thanks for the answer squillman. Express wont cut it - but adding a second instance (Developer Edition) to sit alongside the default Standard Edition instance might be a good call! (this would also allow checkdb to use all processors which are otherwise redundant (mirroring redo is single thread on Standard Edition). – SuperCoolMoss Jun 27 '09 at 19:30

If it truly is used only for disaster recovery, it does not need a SQL license as long as the DR box does not have more processors than the production server. You can install the same edition of SQL as your production server, not higher. If you fail over to the DR box, you have 30 days to restore to the primary server. See the Active/Passive licensing question here, it references log shipping specifically, but applies to all Active/Passive failover models to the best of my understanding. The only possible gotcha is you need to be processor-licensed on the primary. More details are on page 2 here [doc]

You do, however, need to license the OS no matter what.

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Thanks for the answer - also trying to squeeze in off-loaded restore checks and integrity checks of the primary database without breaking the licensing model. – SuperCoolMoss Jun 27 '09 at 22:55

Go and buy a single server license (CAL Based). It comes with 5 CALs which will be enough for your DBAs to use to connect and will only cost a few thousand. Since all you want to do it restore and checkdb the machine you can get away with the Workgroup edition which costs even less.

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