How often do you upgrade your storage array software?


Upgrades are scary!

Having managed and implemented upgrades on highly available systems such as the old Sun StorageTech line of rebranded HDS USP/VSP arrays back in the day, I can tell you that we did not take upgrades lightly!

Unless there was a very compelling reason for an upgrade, the line taken was always “if it ain’t broke, don’t fix it”, but then we were looking after storage in a massively high security environment where even minor changes were taken very seriously indeed. When it came to storage we didn’t have or need anything very fancy at all, just a some high performance LUNs cut from boat loads of small capacity 15K drives, a bit of copy on write snappage to a set of 3rd party arrays and some dual site synchronous replication. Compared to some of the features and configurations of today, that’s actually pretty minimal!


Now this approach meant that the platform was very stable. Great! It also meant that because we only did upgrades once in a blue moon, the processes were not what you might call streamlined, and the changes made by each upgrade were typically numerous, thereby running a pretty decent risk of something breaking. It was also key to ensure that we checked the compatibility matrix for every release to ensure that the 3rd party arrays would continue to function.

They say that software is eating the world. I’d say it seems the same could be reasonably said for the hardware storage vendors we saw at Storage Field Day 8, as they seem to mostly be moving towards more Agile development models. Little and often means lower risk for every upgrade as there are fewer changes. New features and improvements can be released on a more regular basis (especially those taking advantage of flash technologies which are changing by the minute!). A significant number of the vendors we saw had internal release cycles of between 2 and 4 weeks and public release cycles of 2-8 weeks!

In the case of one vendor, Pure Storage, they are not only releasing code every couple of weeks, but customers have obviously taken this new approach on board with vigour! Around 91% of Pure’s customer base is currently using an array software version 8 months old or less. An impressive stat indeed!

This is Hardware. Software runs on it...

This is Hardware. Software runs on it…

This sounds like a relatively risky approach, but they mitigate it to a great extent by using the telemetric data uploaded every 30 seconds to their Pure1 SaaS management platform from customer arrays, building up a picture of both individual customers and their customer base as a whole. They then use their fingerprint engine to proactively pre-check every customer array to find out which may be susceptible to any potential defect in a new software release. Arrays which pass this pre-check have the upgrades rolled out remotely by Pure Storage engineers on a group by group basis to minimise risk. Obviously this is also done in conjunction and agreement with customers change windows etc. You wouldn’t expect your controllers to start failing over without any notice! :)

If I’m honest I am torn in two about this approach. The ancient storage curmudgeon in me says an array should just sit in the corner of the room quietly ticking away with minimal risk to availability and data durability (at least to known bugs anyway!). This new style of approach means that it doesn’t matter how many redundant bits of that rusty tin you have, as Scott D Lowe said last week:

That said we need to be realistic, we don’t live in ye olde world any more. Every part of the industry is moving towards more agile development techniques, driven largely by customer and consumer demand. If the “traditional” storage industry doesn’t follow suit, it risks being left behind by newer technologies such as SDS and hyper convergence.

There is one other key benefit to this deployment method which I haven’t mentioned of course; those big scary upgrades of the past now become minor updates, and the processes we wrap around them as fleshy sacks of water become mundane. That does sound quite tempting!

Perhaps upgrades aren’t that scary any more?

I’d love to hear your opinions either way, feel free to fire me a comment on twitter!

Further Reading
Some of the other SFD8 delegates have their own takes on the presentation we saw. Check them out here:

Dan Frith

Scott D. Lowe

Pure1 Overview at SFD8

Disclaimer/Disclosure: My flights, accommodation, meals, etc, at Storage Field Day 8 were provided by Tech Field Day, but there was no expectation or request for me to write about any of the vendors products or services and I was not compensated in any way for my time at the event.

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