Snapdrive, preferred IP address, which one to use?

[#1]

My SQL 2008 R2 server runs as a VM with an NFS datastore on what I call filer2. This filer has two IP addresses:

10.121.125.121 which is the public network

10.121.126.121 which is the storage network

Of course, this is really just the C: drive of my SQL server. I have four other drives on my SQL server that are used to house the SQL system databases, user database, log files, and SnapInfo directory (used for SMSQL). These 4 drives come from 4 volumes housed on what I call filer1. This filer has two IP addresses:

10.121.125.120 which is the public network

10.121.126.120 which is the storage network

I have Snapdrive 6.3 installed on the SQL server and want to configure the preferred IP address. The question is which one do I use? Right now I picked 10.121.126.120. I figured that Snapdrive is interacting with my SQL databases and logs which are stored on filer1. I also figured that Snapdrive works across the storage network link not the public network. Not sure if I have this correct.

[#2]

It's my understanding that the 'Preferred Interface' is the interface used for Snapdrive to exeute API commands on the filer.

This may be a different address than used for iSCSI data. You might want to use a different interface to keep your command traffic out of band from your data traffic, as it would be in

a FC SAN environment.

I hope this response has been helpful to you.

At your service,

Eugene E. Kashpureff
ekashp@kashpureff.org
NetApp Instructor and Independent Consultant
http://www.linkedin.com/in/eugenekashpureff

(P.S. I appreciate points for helpful or correct answers.)

[#3]

So in my case, the SQL database and logs are on what I am calling filer1. The preferred IP address should not be the once carrying my storage traffic for filer1 (in my case NFS shares) but rather on the public network (10.121.125.120). Is that correct?

[#4 · Accepted solution]

Yes - It could be.

The other IPs you described as 'public'. You might not want to for security resons.

From the Snapdive Best Practice Guide:

Q. How can I ensure that SnapDrive traffic         is routed to the correct interface on the storage system?

A. Configure each network interface on the storage         system by IP address rather than by host name. You can use SnapDrive to         set the preferred         IP address.

Using a host name might work (SnapDrive will try to resolve it to an         IP address), but there is no guarantee that it will: SnapDrive might not         be able to discover the IP address and, if it does and there is more than         one NIC, there still might not be a way to know which was intended.

As of SnapDrive 3.1, configuring the interface by IP address ensures         that SnapDrive traffic is routed correctly.

Note: There is an additional consideration if you are         using the iSCSI protocol. By default, any IP interface on the storage         system, including the storage system's 10/100 e0 interface, will accept         iSCSI commands, and this might not be what you want. To ensure that all         iSCSI commands are processed by the storage system's GbE or Fast Internet         interface, disable iSCSI processing on e0 by means of the following command:

iswt interface disable e0

Caution: Do not allow this command to complete while         there are active iSCSI sessions connected to the e0 interface (the storage         system warns you when you issue the command if this is the case). You         must first disconnect those sessions from the host, and that might entail         scheduled downtime to allow you to shut down the applications using the         affected LUNs.

I hope this response has been helpful to you.

At your service,

Eugene E. Kashpureff
ekashp@kashpureff.org
NetApp Instructor and Independent Consultant
http://www.linkedin.com/in/eugenekashpureff

(P.S. I appreciate points for helpful or correct answers.)

[#5]

I have verified with Netapp that the IP address to use the the public or management network address for the filer that houses the SQL databases and log files. In my cases this is 10.121.125.120

Thanks for your help