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Stretching SVC to meet new business availability needs.

January 18, 2013 Leave a comment

IBM has been secretly working on a technology that is changing the way administrators will deploy their VMware environments.  SAN Volume Controller (SVC) Split Cluster solution allows live application mobility across data centers based on VMware Metro vMotion. This solution can now alleviate unplanned outages as well as provide additional flexibility.

SVC can now support a split cluster configuration where nodes can be separated by a distance up to 300 KM.  This type of configuration does require clustering software at the application and server layer in order to failover to a server at the corresponding site in order to continue business and resume access to the disks. SVC will keep both copies of the storage in sync and mirror the cache between both nodes so the loss of one location does not disrupt data access at the other site.

The next big advantage SVC has is a small quorum disk that can allievate any split-brain issues.  Split-brain problems occur when nodes are no longer abale to communicate with each other and they start allowing writes to their own data.  SVC creates a tie break from a third site in order to ensure the survival of at least one location.

The SVC Split Cluster configuration uses a term called failure domain.  This allows the SVC cluster to know which components are in a certain boundary where any failure may occur (ie power, fire, flood). The entire SVC Split Cluster must comprise of three such boundaries, two for the storage controllers containing the customer data and a third for the active quorum disk.

Using VMware’s VMFS file system, the SVC can supply access to all of the vSphere hosts in both locations. During vMotion, the virtual machine can switch to a new physical host while keeping the network identity. By using the Metro vMotion to migrate VMs, customers can now plan for disaster avoidance, load balancing as well as data center optimization of power and cooling.

This solution is also for customers looking to add high availability with in their single datacenter. Imagine two servers in different parts of the data center. They could be on different power feeds and different SAN fabrics. You can now provide continuous availability to these servers with out having an administrator called in the middle of the night.

For more information about SVC Split Cluster and even step by step instructions on how to setup the SVC, VMware and Layer2 network check out this Redbook.

Now available is the IBM System Storage N series with VMware vSphere

December 12, 2011 Leave a comment

 

 

Now available is the IBM System Storage N series with VMware vSphere

 

Redbooks are a great way of learning a new technology or a reference for configuration.  I have used them for years not just in storage but for X series servers and for software like TSM.  The people that write the books spend a great deal of time putting them together and I believe most of them are written by volunteers.

This is the third edition of this Redbook and if you have read this before here are some of the changes:

Updated information:

-Latest N series model and feature information.

-Updated the IBM Redbook to reflect VMware vSphere 4.1 environments

New information:

-Information for Virtual Storage Console 2.x has been added

This book on N series and VMware goes through the introduction of both the N series systems and VMware vSphere.  There are sections on installing the systems, deploying the LUNs and recovery.  After going through this Redbook, you will have a better understanding of a complete and protected VMware system.  If you need help with how to size your hardware there is a section for you. If you are looking to test how to run VMs over NFS, its in there too!

One of the biggest issues with virtual systems is making sure you have proper alignment between the system block and the storage array.  This will negatively impact the system by a factor of 2 in most random reads/writes as two blocks will be required for one request.  To avoid this costly mistake or to correct VMs you have already setup a section in the book called Partition alignment walks you through the entire process of correctly setting the alignment or fixing the older systems correctly.

Another area that I will point out is the use of deduplication, compression and cloning to drive the efficiency of the storage higher.  These software features allow customers to store more systems on the storage array than if they used traditional hard drives.  Also there is how to use snapshots for cloning, mirrors for Site Recovery Manager and long term storage aka Snapvaults.  At the end of the book are some examples of scripts one might use for snapshots in hot backup modes.

Whether you are a seasoned veteran or newbie to the VMware scene, there is a great guide that will help you from start to finish setting up your vSphere environment.  The information is there, use the search feature or sit down on a Friday with a high-lighter, which ever fits your style and learn a little about using a N series system with VMware.

 

Here is the link to this Rebook:

 
For more information on Redbooks go here!