SnapCenter SQL Plug-In Host Log Directory vs. SMSQL SnapInfo

[TMADOCTHOMAS]

We are gearing up to transition from SMSQL to the SnapCenter SQL Plug-In. If I'm reading correctly, a LUN for the Host Log Directory replaces the SnapInfo LUN from SMSQL. My question for anyone who's done this - can this be the same LUN? In other words, can we point the Host Log Directory to the same LUN we hosted SnapInfo on, and later delete the SnapInfo content off of the LUN? Is there any reason this wouldn't work?

[mrahul]

Hi  TMADOCTHOMAS,

    The only requirement is that Host Log Directory should be a LUN from NetApp Storage.

Once you transition to SnapCenter, you may configure your SQL plugin host and assign the host log directory to the same disk/lun. There is no limitation in that. But please do make sure that the disk will be from now on used solely by SnapCenter. Please do cleanup the disk before starting to work on SnapCenter SQL workflows.

[TMADOCTHOMAS]

Thanks @mrahul!  One of the things you said was:

"But please do make sure that the disk will be from now on used solely by SnapCenter. Please do cleanup the disk before starting to work on SnapCenter SQL workflows."

So essentially we would need to point the Host Log Directory to the LUN, delete the SnapManager for SQL content on that LUN, and then start using it with SnapCenter? I was hoping to retain the data for a day in case we needed it.

[TMADOCTHOMAS]

@mrahul (or anyone else), I have a follow-up question. Obviously our deployment got delayed 🙂 but we are picking it back up this summer.

I just re-read the documentation and read something surprising:

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"You can set up one log directory per host. You cannot set up a log directory per instance."

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Is this accurate? In our existing SnapManager for SQL setup, we have one log directory per SQL instance.

Also, I'm not clear on what this line means:

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"In a Windows cluster environment, you must configure a host log directory for each host. For an
SQL cluster, you must set a host log for the Failover Cluster Instance (FCI)."

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We have SQL instances running on a Windows Failover Cluster. Is this the same thing as a SQL cluster in this terminology, or is a SQL cluster considered something completely different? In other words, do we need this additional host log for the FCI (and if we do, can it be the same LUN as the host log directory)?

[mrahul · Accepted solution]

SQL instances running on a Windows Failover Cluster/SQL cluster is essentially referring to SQL FCI instance. "In a Windows cluster environment, you must configure a host log directory for each host" --> This is required only in case the individual nodes/host are having any Standalone SQL Instances. Else you can select the Cluster and set the host log directory for your FCI Instance.

[TMADOCTHOMAS]

@mrahul thank you very much! That answers my question.