I’ve come across a number of customer sites that have only a single backup stream from each client running sequentially to a tape drive device.  While there is a concern that the time to recover increases if you have multiplexed data on a tape, there is also a need to properly stream the tape drive.  For the most part these nice little pieces of hardware do not have a slow speed and will be required to stop and restart as data is presented.  This is known as “shoe shining” and can take a large toll on the device resulting in frequent repairs and even slower backups.

The following examples expand each step in multiplexing backups to illustrate how all tape drive devices should be used.

1. Each example shows 5 Clients, each client having 4 possible jobs streams
2. Each stream runs at 5 MB/Sec
3. Tape device can handle 80MB/Sec

Figure A
The example in Figure A shows the consecutive approach currently deployed causing a cascading slow down affect.  There is simply not enough data being presented to the tape drive for it to stream effectively.

Figure B
The example in Figure B is an improvement as each client can send a backup to the tape drive, shortening the overall backup window, and utilizing the tape drive at 20MB/Sec.

Figure C
The examples in Figure C and D show the possible configuration should the specific client not be able to handle multiple data streams or if everything could be sent to the tape drive at the same time.  The bottom right needs 100MB/Sec, but with only a slight compression ratio this scenario would keep

Figure D
the tape drive streaming at an optimized rate.  If the original example had each stream taking one hour, the backup window would need to be 20 hours to complete; where as the final example could finish all backups in only 1 hour.

And a few parting thoughts when considering a new backup solution, in general:

We strongly encourage customers to explore reference architecture design alternatives before choosing a specific product for deduplication. In most cases, backup architecture redesign is the best way to maximize re-use of existing backup assets and take full advantage of next generation backup technologies, such as VTL and deduplication. In addition, performing a vendor-neutral performance and sizing analysis for core and remote sites is the only way to properly plan for deduplication both from a technical and budgetary perspective.

-John Merryman, GlassHouse Service Director

a

Tape Elimination (VTL and encryption)

Many of our customers are modernizing backup architecture, with the goal of minimizing or even eliminating tape. Mitigating media loss risk, simplifying operations, and improving disaster recovery are key drivers for tape reduction in core and remote backup environments. Many customers are embracing VTL and deduplication/replication as an outright alternative to tape encryption. The typical reference architecture we develop in the field with mid-large enterprise customers still includes tape, yet repositions tape to store data of certain type and value, and for many customers significantly restricts the physical movement of offsite tape. Tape is being eliminated from remote site backups all together, given appropriate WAN bandwidth for replication of deduplicated data.

-John Merryman, GlassHouse Service Director

Archiving

Should backup and archive be the same service? The GlassHouse general position is ‘no’, however every environment faces need for long term retention of data, and in lieu of a true enterprise archiving platform, backup data retention is the only option for many enterprises. In general, we see tape playing a valuable role for long term retention of data, and most vtl/deduplication vendors tend to agree with this position. Operationally, backup and archiving should be logically segregated, with archives treated clearly as the exception than the rule with a clear distinction made between server archives (to backup environments) and true archives, such as those found in email or database archiving systems.

-John Merryman, GlassHouse Service Director

Data replication and DR solutions

The impact of disk based replication of deduplicated data has a profound impact on backup architectures and their role in disaster recovery. The traditional backup environment today uses offsite vaulting for tape, and disk or host based replication for more aggressive disaster recovery capabilities. The role of backup in disaster recovery can be significantly enhanced through any combination of backup software or hardware deduplication and replication schemes.

-John Merryman, GlassHouse Service Director

• Data Deduplication
  • Data deduplication is one of the most disruptive technology features to affect enterprise backup. This technology feature makes disk economical for backup data storage, and opens up options for remote site and core data center replication, previously unavailable. Software and hardware based deduplication have distinct differences in terms of scale/performance/capacity, and should be applied appropriately to production backup needs. The vendors are typically very aggressive positioning all technologies to do all things, and the amount of vendor hype, poor information, and quasi-solution designing is absolutely staggering.

-John Merryman, GlassHouse Service Director

I’ve spent over 17 years working in the backup space starting out as an evening ‘Tape Jockey’ contracting for Digital Equipment Corporation.  I’ve heard over that time that the profession of administrating a backup environment was “the most important job that no one wants”.  This concept has held true for a long time and has also intrigued me as to why people have shied away from it.  From a near primal approach if data is worth being saved to disk then assuredly it’s worth making a copy of.  Hasn’t everyone lost something thought to be saved and would like it brought back?

Now to say that you need to have the meeting minutes from last Tuesday, which were of course accidently deleted, back before this week’s agenda shows you missed an actionable item is obvious.  On the surface restores from these backups can keep the day to day business running since having information readily at hand can mean the difference.  When you pull back a layer you find that there are far more corporate and legal reasons for keeping and being able to access information over the long term.  These include government regulatory requirements based on the type of business and data that is being protected.  There are also binding agreements with customers and clients that warrant the retention of data.

The how to retain data, for what retention periods, and the need to bring it back will be topics of future blog postings.  If you’re a backup person or are just interested the art, stay tuned for more details from nearly two decades of living it.

-Richard Witherow, GlassHouse Senior Consultant

The great thing about running a Mom & Pop store is the familiarity of everyone who comes to the store. Mom and pop know everything that’s on the shelves, and also know all of the customers and their needs for every visit. Mom and pop have what’s referred to as transparency into their market. Their supply of commodities is mapped to the smallest detail, and they have specific knowledge of their customers’ needs. Imagine a Mom & Pop storage department. It’s small, customizable, and administratively ad-hoc for every customer’s data protection needs. Now imagine what happens when mom and pop expand and grow into an enterprise IT infrastructure with data centers all over the world, and Peta bytes worth of data storage stocked on the shelves.

When companies are small it’s easy to keep track of which data needs what level of service. Large companies, on the other hand, span the globe and consist of incredibly complex environments including infrastructure, process, people, and skills. It’s impossible for organizations to survive on a global scale with that small business mentality, so why is it then that large companies resist finding transparency in their IT backup market?

For one, large businesses are just that – large. Infrastructure, people, departments, and applications are many and varied. Storage/backup staffs are much more concerned about day-to-day operations and issues than they are in any proactive strategy for the business unit next door. This in turn lends to a silo mentality, where every piece of the organization is concerned only about their needs and goals. Because of the blinders put up around the silo, a zone of control is also established that other groups and departments, especially storage, have difficulties penetrating. This silo phenomenon creates a culture within the business that hinders process and change, thus creating solid, opaque walls without any windows of transparency.

To correct this, storage teams need to take a more trickle down approach to communicating strategies. Begin at the upper most levels of management and communicate the benefits of a service strategy in a compelling way. The ocean doesn’t boil in a day, but a weak message also won’t impress anyone with clout. Specific targeted goals that run the middle ground are necessary to break the silo walls, and ease the ingrained fear of change in what’s perceived as an impossibly complex environment.

-Brian Sakovitch, GlassHouse Consultant