Multi-site Failover cluster using EqualLogic SAN

[chicagotech]

Situation: We have a website/PEO (Patron Edge Online) running SQL 2005 on our DMZ. The server has some issues and we are required to re-build it as high-availability and failover server/website running 24/7.



Design: Our design is based on Microsoft article:

Example Clustered Service or Application in a Multi-Site Failover Cluster: http://technet.microsoft.com/en-us/libr ... 7519(WS.10).aspx.






1.There are two Dell R510 servers running Windows 64 bit 2008 R2 Enterprise with Hyper-V enabled. One is in Building A and another one is in Building PSC
2.Each Dell R510 server connects to one EuqalLogic SAN.
3.Each Dell Server has 12 NICs and 48GB RAM.
4.The Clients are in VLAN 1, the Dell R510 servers and PEO/VM are in VLAN 10/DMZ, the SAN is in VLAN 800.
5.We will use EqualLogic software to replicate data/VMs between two sites.
6.The PEO will run Windows 2003 R2 Enterprise and Microsoft SQL 2005.

Consideration: We believe we have knowledge to create a Multi-Site Failover Clustering. However, we don’t have experience to use EqualLogic replication software and experience to build a Multi-Site Failover Clustering. We have the following questions for you.

1.Does our Multi-Site Failover Clustering meet the requirement of high-availability and failover server/website running 24/7? Or is it workable?
2.Do you know if the EqualLogic replication software will work for this design? Or do we need other 3dr party software?

[chicagotech]

The fact that you are running Windows 2003 makes multisite clustering a little more difficult as the solution needs to be on the Hardware Compatibility List (HCL). The other issue is with the Equallogic Storage Replication, you will have to check with Dell to see if they have multisite cluster integration as I couldn't find mention of it online.

If you are looking just to protect against hardware failures I would say you should probably consider Hyper-V host based clustering instead of clustering within the guest. This will simplify the implementation and get you past the HCL requirements. If the Equallogic arrays don't support multisite clustering natively you will have to look at other solutions such as SteelEye DataKeeper CLuster Edition for your replication and cluster integration.

I wrote a Hyper-V multisite cluster Step-by-Step article in my blog, Clustering for Mere Mortals.

David A. Bermingham, MVP Senior Technical Evangelist, SIOS Technology Corp

[chicagotech]

Host clustering refers to physical server clustering. This can be SQL Server, Exchange, ... and also a Hyper-V cluster. This provides high availability for the nodes of a virtualization cluster based on Hyper-V, hence the name host clustering (the physical machines that host the virtual machines). However this does not give you application high availaibility, for that you need to cluster your virtual machines running the application. What type of clustering your need there depends on the application, but since you're talking about SQL Server 2005& Windows 2003 if wil be MS Failover Clustering using SQL server installed in Virtual Machines, which is called guest clustering. It seems that for your needs you will need both.

Hope this helps,

Didier Van Hoye

http://workinghardinit.wordpress.com

[chicagotech]

Didier is correct in his description. If you need to ensure the application is monitored you must cluster inside the VMs with Windows 2003 MSCS. However, if you are only concerned about hardware level failures of your physical servers then you can do host based clusterering with Windows Server 2008 WSFC. Let me know if you have questions - I'd be glad to jump on the phone with you.