The Storage Economist

I was working on my taxes two weeks ago, and as usual ended up humming the Taxman song from the Beatles. Part of the lyrics penned by George Harrison goes as follows: “Let me tell you how it will be; There’s one for you, nineteen for me. ‘Cause I’m the taxman, Yeah, I’m the taxman”. Perhaps our income tax rate is not 95% here in the US, but I am interested to note personal income tax levels from different countries around the world.

I also find interesting an apparent tax rate that we pay related to un-utilized storage capacity.  I have written about the cost of waste before and the options (virtualization, thin provisioning) that are available to reduce the rate of wasted capacity.

We all realize that it takes many GB of actual raw disk capacity to store a single GB of data — many times more. Especially when you factor in:

• RAID overhead
• Reserve capacity held by the storage admin
• Reserve capacity held by the DBA or application owner in what is used vs. what is allocated
• Usable vs. allocated waste
• Replication or copy space (this is not wasted capacity, but will increase the total GB needed)

I often see IT operations reports on metrics that shows this written-to-raw ratio. This can be a damaging or embarrassing metric to show management, but it can underscore the need for a more advanced architecture and operational process related to storage allocation and usage.  The written-to-raw ratio is simply a measurement of the first instance of data written to disk compared to raw capacity purchased to store that original data.

One of our storage economic black-belts here at HDS is Reg Mills. He recently shared with me some analysis where a customer had a 16:1 (raw to written ratio). Not quite as bad as the taxman, but darn close. Here is an excerpt from his work:

TCDO we often discuss, but rarely do we get real client numbers to show the effect in his own world.  In a recent Storage Economics workshop I was having my challenges around getting some significant hard savings around a new virtual architecture, looking for some avenues to identify some deeper hard cost saves to build a viable business case, I asked the storage team to prepare the vendor-based utilization reports.  Analyzing the reports identified a 16X TCDO between raw array storage and the used server storage (data).  Using this as a discussion point that $6 per GB raw (for purchase) was really costing them $96 per GB for data stored, and the focus should be eliminating the highest cost waste in the server through reclamation, we were able to identify over $2M in savings. Some of the key points in this 16:1 ratio:

• Using the client’s own numbers (16X and $77 per GB) got them immersed in the storage economics approach and metrics
• In accounts willing to give their utilization reports, we can reasonably quickly identify the TCDO and the related reclamation story
• Savings to reclaim space (and therefore grow into current capacity) can be archived with a combination of software ( HDT, HDP and others) as well as a new virtualized core storage array with VSP
• TCDO also uncovered additional potential saving opportunities at each abstraction layer of storage to address/discuss.  In this situation we selected to only focus on Thinning/reclamation
• By reclaiming current space waste, the new storage curve drops down permanently.  Through use of reclaimed space waste over the next 2 plus years no storage purchases are required, then once reclaimed storage is fully utilized in year 3 the new purchase curve has a much lower 6:1 ratio requiring purchase of significantly lower storage quantities.
• This next chart shows business at usual (BaU) with storage growth when you have the 16:1 waste-taxation rate. With a new architecture (shown in blue) the same effective (virtual and physical) capacities can be presented but with a much lower tax rate. The blue line is an HDS architecture using array virtualization, thin provisioning and dynamic tiering.

So if you think the taxman rates are high, take a closer look at your own cost-of-storage-waste-taxation-ratio to see where you stand. The impact and benefit of reclaiming some of that waste and changing your storage demand appetite should be a positive message to your management. Especially during tax season.