Failover isn’t Just for Disasters Anymore: Migrations and Provisioning using Dynamic Infrastructure

I have noticed a growing trend implementing disaster recovery solutions for Fortune 500 companies’ IT infrastructure over the last seven years: data center managers want to do more with the controls they have implemented for their business continuity plan. They have disaster recovery solutions in place, but are looking to those same solutions for recovery in the event of a disaster and asking them selves “How can I use this to help with daily operations or little “d” disasters?” The rapid adaption of Dynamic Infrastructure utilized by Double-Take® Software is giving data center managers the ability to help maintain their Business Continuity Plans (BCP) and help facilitate projects such as server, hardware or complete data center migrations.

Dynamic Infrastructure is the ability to move any data, any server, anywhere, anytime with minimal impact to business operations. Data center managers are now using the controls implemented for their BCP to move servers in real time from older, lower- performing servers to new high performance servers; moving from physical to virtual, moving many servers from a local server in the same data center or to a co-location across the street. The controls originally implemented to enable failover are now becoming a data center maintenance necessity - and not just in the event of a disaster. So, failover isn’t just for disasters anymore.

A few customers that I have helped recover realized that having the ability to failover both the data and system state from one server to another similar server (with different hardware) made them realize that they could now move data anywhere, and fail forward at anytime, anywhere without any disruption to their users and or business operations. Now data center managers are asking themselves; “How else can I use business continuity controls for my daily operations?” A few have utilized dynamic infrastructure to move entire data centers – with great success.

Dynamic Infrastructure is becoming ever more important with daily data center operations and the adaptation of virtualization for the disaster recovery center. Virtualization is helping reduce the overall footprint required for the number of servers needed to protect a data center, as well as reducing power, space and overall hardware requirements. Because Dynamic Infrastructure allows you to move data between dissimilar hardware you can easily move from physical to virtual and back again. Many operation managers are just using real-time replication to move from physical to virtual, minimizing any downtime that typical P2V processes require, and keep those systems on the virtual infrastructure. Migrations have now become routine and is easily accomplished with minimal impact to user access. It wasn’t that long ago that the mere mention of the word “migration” (whether it was data, server, hardware or OS) made IT managers wince. The issue with migrations in the past was mostly due to compatibility and not realizing there were compatibility issues until you reach “point of no return”. And you didn’t have any choice to back out -so you forged ahead and tried to work through the driver, hardware or software compatibility issues as they arose. Dynamic Infrastructure has intelligently reduced the typical risks of migration and provisioning by using auto discover features, automating much of the provisioning, and more importantly providing the ability to return to the original production version if needed. Eliminating the proverbial point of no return is pretty important when attempting to migrate systems for any purpose.

Dynamic Infrastructure also eliminates the distance requirement for most other solutions. Hardware migrations as well as most virtualization solutions usually need to be in the same building. For example, if you are looking to replace an older CX series SAN with a newer iSCSI standard design you almost certainly need fibre links between the two systems and they would likely need to be in the same building to prevent network latency from impacting the data transfer. The same goes for moving systems between virtual servers whether using VMware® VMotion™ or other virtualization tools.

Whenever significant distance is involved between servers there are several things to consider.

• Bandwidth throughput
• IP latency
• Volume of data
• Transactional change rate of the data
• Disk write speed at the target location

This is less of a consideration when using Dynamic Infrastructure because there are options available that minimize the above listed items:

• Bandwidth scheduling is available to allow data transfers to occur during your peak production periods when less bandwidth is available for systems transfer.
• Transfer compression is available that can compress typical database transactions by upwards of 80% less than a normal file or block copy you may see with some synchronous transfers.
• Asynchronous replication has less of an issue with IP latency than other data transfer systems because it doesn’t require and return acknowledgement that the data has been written on the other side before sending the next set of data for transfer.
• Because Dynamic Infrastructure mitigates the top three concerns with distance, the volume of data becomes less of an impact. Typically, data transfers for a P2V conversion requires downtime for the system that is being converted which requires the data transfer to be completed usually over a weekend or scheduled change control period. So you might have 48 hours maximum (more than likely you don’t have that long) and transferring a few terabytes of data just isn’t going to move that fast.
• If bandwidth isn’t a concern then you have to account for the amount of data that can be written to disk. I have heard several customers state “I have fibre” or “gigabit network” - which is great - the throughput won’t be an issue. However, if that 7200 RPM drive in the system you are transferring to can only write 20GB per hour then that will be as fast as that data will move. I have seen some Fibre array SANs that will scream a data transfer at 65 gigabytes per hour, but that is under ideal circumstances and probably not conservative enough for planning purposes.

Because Dynamic Infrastructure is real-time data transfer there isn’t any downtime or deadline that is required to move the systems in order to keep them current. You can start moving a terabyte system on a Monday, throttle the bandwidth utilization to only use what you specify and let it run. Set it and go and let it notify you via SMTP messaging when it is complete and ready to failover to the new system. And the greatest thing about this is that you are capturing all the changes the users made during that transfer process. When the initial synchronization is complete you are confident that you have the most recent and current set of data. If this was a P2V conversion process or a restoration from tape you would have some length of downtime during the conversion or restoration process and then you would have to prevent your users from accessing that system during the process or determine how you would update the target systems with the incremental changes that occurred during that restoration period.

Failover, thanks to Dynamic Infrastructure, becomes a choice over necessity and maintenance over disastrous event. There isn’t a need to wait for the disaster to introduce itself before you start exercising your failover process. Any good BCP should be exercised at least every six months, if not after each change control outage, to see if any modifications need to be made. This also allows the BCP controls to be used for day-to-day operations, which ensures the familiarity with the failover and failback. The failover process is now an essential part of provisioning, migrating or just moving systems to improve performance, and processing either near or far without limitations. Dynamic Infrastructure is the ability to move systems from a data center anytime, anywhere, for whatever purpose. Systems are moved where ever needed for the purpose of provisioning, building co-location facility, enhancing hardware or application performance or performing routine maintenance without interrupting business operations. This not only helps day-to-day operations for data center managers but may ultimately facilitate the protection of systems for cloud computing.