SQL Availability
You know you can no longer rely on those dependable restores from tape for a number a different reasons, including bad tapes, restoring to different hardware, etc. How can SAN technologies such as Snapshots help? How does SQL 2005 running in a Windows 2003 provide you with application consistent recovery? Should I consider SAN replication?

So once you finally get your iSCSI SAN from EqualLogic, you really are getting all of the right tools to enable all of the requirements listed above without paying any premium for the features.

When you create those snapshots and you are running MS Windows 2003 and SQL 2005, EqualLogic has the ability to call up the VSS (Volume Shadow Copy Services) API and in an instant release to the SAN, the data is in a consistent manner. That way, if you need to recover from any given snapshot, you can recover the SQL database without the need to do a consistency check, which, depending on how large your database is, could take from minutes to hours for your users to be able to finally connect to their data.

Once you have these snapshots in your SAN, EqualLogic then allows you to replicate to another array at a remote site for no additional costs and still maintain application consistency.

iSCSI vs. Fibre Channel
So you’ve heard of fibre channel SAN technology but what is all of this hype with iSCSI? Is it really faster than fibre channel?

This is really a hot topic. Like me, you are getting bombarded with fictional statements from all of the fibre channel SAN manufacturers. So let me provide you with real data so the next time you get a call from any of these fibre channel vendors telling you that if you need performance, you really should stick with fibre channel technologies, you can have an interesting conversation.

Here Is Some Data

Fibre Channel

• 1GB = 100MB – Actual payload is 96MB
• 2GB = 200MB – Actual payload is 192MB
• 4GB= 400MB – Actual payload is 384MB

iSCSI

• 1Gb= 124MB – Actual Payload is 116MB
• But with 2 NICS teamed – 2 x 1GB = 232MB … FC 192MB
• 10Gb = 1240MB – Actual Payload is @ 1160MB

So if you really compare this at the protocol layer, you can see how to achieve fibre channel speeds by just using NIC teaming technology which comes with all of the servers today.

Comparing 4GB fibre channel to teamed NIC you can clearly see that fibre channel is faster than iSCSI over 1GB, but the issue is that your open systems do not have the ability to handle that kind of throughput. So in essence, it is like adding a 10 lane highway but you can only use one.

Consider then how 10GB is going to affect 4GB or even 8GB fibre channel. 10GB NICS are now readily available in the market and vendors like EqualLogic will be developing their controllers to support this technology. So the question for you is, if that’s the case then why would you still consider fibre channel for your SAN storage needs?

Now that you have been armed with all of this data, you should feel pretty comfortable answering those phone calls from all of those fibre channel vendors.

If you want to learn more about:

• Limitations of Traditional storage methods
• Performance Challenges
• Storage Options
• Back up and Archiving Tips

Please check out our recent webinar presetation, “Optimizing Storage for SQL and SharePoint” www.greenpages.com/company/Managing-SQL-and-Sharepoint-SAN.ppt

Have fun!