Storage Nation

Last week’s news reports that COPAN Systems are back from the dead after their purchase by SGI.  The newly branded arrays have been tweaked (for example 50% of drives can be spinning on the SGI incarnation) but essentially the concept is the same; store shedloads of inactive data.

This is a series of posts covering the subject of Storage Management.  Previous posts: The Four Pillars of Storage Management Four Pillars: Service Four Pillars: The Service Catalogue In any system, resources are finite.  There is always a limitation to what is available.  However there’s also a truism that states if resources are free then they will be consumed at an infinite rate.  So it is with storage.  Someone has to pay for the storage resources that are placed on the floor.  If customers are not charged in some way for their consumption of storage, then they will continue to consume resources ad infinitum.  The solution is to implement chargeback or, to be more precise, billing. Definition It’s worth pausing for a moment and discussing the terms Chargeback and Billing .  When computing was first made available as timesharing, customers were billed for their usage of the shared system.  The billing unit may have been time, CPU resources or some combination of metrics that represented utilisation.  Mainframe resources were so expensive that there had to be an efficient charging mechanism.   The concept of billing is something that was intrisically built into the mainframe design and even to this day, resources can be tracked using records produced by SMF ( System Management Facility ) and reported on through RMF ( Resource Measurement Facility ).  So billing represented a method of charging for usage that wasn’t directly related to the underlying hardware

I’m not a fan of making press releases on behalf of other companies however once in a while, a news item catches my interest.  So it is with the announcement of the Violin Memory Inc. 3200 series of all-memory storage arrays.  Why are these interesting?  Because I think they are moving and potentially blurring the boundaries between spinning drives and memory-based permanent data storage

Despite my doubts about its usefulness, on my recent holiday in the US I purchased a shiny new iPad.  OK, over the last few week’s I’ve talked about how I couldn’t see the point of the platform, but two things conspired against me; (a) I love technology (although I stop short of calling myself a geek) and (b) reverse peer pressure from my family goading me about my inability to walk past technology without acquiring it, tipped me over the edge.

I case you didn’t know, I’ve been on holiday since the beginning of April.  I was expecting (after two weeks of rest and relaxation) to be heading off to a new and potentially challenging piece of work.  Unfortunately that work is no longer there.  Not only is the work not there but neither am I – I’m still in the US with my family and can’t travel due to the restrictions in place on aircraft after the volcano eruption in Iceland. In the space of less than a week, I’ve had to put contingency plans into place for both work and pleasure.  We’re lucky; we hadn’t left to go to the airport and so have managed to stay in our accommodation in San Diego.  A two week holiday will simply turn into three; school will have to wait for my wife and children

I case you didn’t know, I’ve been on holiday since the beginning of April.  I was expecting (after two weeks of rest and relaxation) to be heading off to a new and potentially challenging piece of work.  Unfortunately that work is no longer there.  Not only is the work not there but neither am I – I’m still in the US with my family and can’t travel due to the restrictions in place on aircraft after the volcano eruption in Iceland. In the space of less than a week, I’ve had to put contingency plans into place for both work and pleasure.  We’re lucky; we hadn’t left to go to the airport and so have managed to stay in our accommodation in San Diego.  A two week holiday will simply turn into three; school will have to wait for my wife and children. As for work, I already have some contingency plans in place and things will work out.  But who could have thought such as “simple” natural phenomena could have ramifications for the whole world? The People Problem For the UK and most of Europe the last two weeks have been Easter holiday time (I believe this overlapped the US Easter holiday too).  Quite rightly people have been enjoying time away, but now without the ability to get back home and the fact that more people are away than usual, the lack of key personnel will be causing problems.  None of these are insurmountable if: Key staff can be contacted while away – not disturbed, mind you but contacted in an emergency.  Even with tools as simple as a Blackberry or iPhone, decisions can be made and confirmed via phone, SMS or email

What an interesting and extremely busy day the first day of the HP StorageWorks Tech Day 2010 proved to be.  The day was a mixture of vision and product demos, providing both the high level and detailed view of current technology and future plans. The itinerary for the day has already been published here .  My highlights for the day included: Tom Joyce outlining some of the challenges facing HP in the storage market.

Finally I’ve managed to post here the first of a number of video clips from the recent HP Blades Day.  Paul Perez discusses my question regarding the management of the range of (somewhat) disparate storage technologies HP have acquired over recent years.  I’m looking forward to discovering more about: The converged management framework and “on-ramp”.

IOPS Per RAID Group, ordered by most to least I took part in a podcast last night that discussed the XIV platform.  One of the “key features” of XIV is the wide striping of data across all spindles.  It’s a concept we’re seeing more and more in contemporary storage hardware architectures and one that’s being shoe-horned into older storage arrays too.  Have you ever wondered what the point is?  Take a look at the following graphic.  It shows the number of write operations per RAID group, ordered by the busiest RAID group to the least active.  It’s real data from a real system.  What you see is the Long Tail effect, where a small number of RAID groups are doing most of the I/O.  In this example, 80% of the workload is performed by 50% of the RAID groups; only 3 RAID groups account for 20% of the workload.

Over the last week there have been a few stories catching my eye.  Here’s a brief paragraph on them. SGI Acquires COPAN Systems In fact to be more precise, SGI have acquired some of the assets of COPAN and left the liabilities behind for a mere $2 million in cash ( press release ).  The demise of COPAN raises two potential questions; is spin-down a dead technology or were COPAN in a market that wasn’t able to understand their technology