StorageRap

OK, lets all go to the moon!

Sunshine at Ocarina had a blog post this morning about the role Nirvanix is playing with NASA's Lunar Reconnaissance Orbiter (LRO) that is orbiting the moon and taking high resolution images of it's surface to prepare for future missions to the moon. 

A week ago I net up with an old friend who works at NASA and he was talking about his work and what NASA was up to.  With the shuttle program ending next year, the push at NASA is to get back to the moon, not for short visits like the Apollo program made, but for extended work and research at a lunar research facility. 

Not everybody likes the idea of pouring resources into an extensive manned program when it would be possible to do a lot of work with robots. But why give robots all the fun when they don't even know what fun is?  More to the point, there is probably a lot to be gained by engaging international teams in this mission. One of the best ways to get a perspective on our earthly situation is to see it from space.  Moving beyond us-versus-them thinking and the resulting conflicts that destroy so much would be a very good thing.  Robots aren't going to help much on that front, so I say let's get on with this work and go to the moon together and find what whatever we find. 

Flash is the least compelling storage technology in ESG survey

Terri McClure at ESG recently blogged about the what technologies are most interesting to NAS customers, according to a survey they conducted last September and October. People following the storage blogosphere may have seen references to Terri's post in blogs written by Sunshine Mugrabi from Ocarina and and Stephen Foskett from Nirvanix

3PAR is not a NAS company, so the survey wasn't a perfect fit, but the results of the survey pertain to more than NAS companies.  There was one data point that I thought was particularly interesting - flash SSDs ranked at the bottom of all the potential technologies people might buy. Instead, survey respondents were far more interested in power, cooling and space efficiencies - in general, doing more with less.

I think Flash SSDs will become more popular over time after the prices become more reasonable, but until then customers are going to continue to look first for products that help them cut costs, as opposed to adding significant costs.  Most customers today are looking for ways to meet their performance objectives while reducing their costs. That's what thin provisioning, wide striped arrays from 3PAR are designed for.

Claus, someone should smack you up for bad math! And the HBP smackups continue

Claus Mikkelsen at HDS wrote in his most recent blog post:

Having a 700% improvement in workload throughput is equivalent to having 105,000 RPM drives (very crude arithmetic and workload assumptions, but you get the point; don’t beat me up on this!).

What??  "don't beat me up on this"  Claus, what sort of lame disclaimer is that??  If you are going to write something stupid - and you know it when you are writing it, don't beg for mercy like a stoolie.  The math checkers in the storage blogosphere will find out and then decide if they want to give you a heaping load of sh%& for it. 

But I'm going to cut you slack because you are promoting wide striping, an excellent technology that doesn't get enough attention.  So, thanks.  We're really good at wide striping in 3PAR arrays and we appreciate the fact that HDS is trying to help people understand how well the technology can work - even if the explanation you provided is screwed up. While I'm at it, let me give you props for this line too:

I’ll defy anyone to manually provision in a way that will outperform the wide striping we do with HDP

A page from the 3PAR hymnal! - except you don't have to be using thin provisioning on a 3PAR array in order to get wide striping.  Automated provisioning in 3PAR arrays provides wide striping that performs much better than can be achieved with manually tuning. Not only that, but the utilization levels with 3PAR arrays are very high - especially for mixed workloads, where customers often want to store data for different applications on different RAID levels or tiers. 

With HBP (HDS Bloated Provisioning) - if application data is stored on different RAID levels you need different pools for each RAID level, which means you have to divide your disk resources between pools, which means your wide stripes aren't as wide and the performance advantages of wide striping are diminished. The other problem with using multiple pools is that utilization tends to be lower because disk resources are leveraged unevenly across different subsets of applications.

Nigel Poulton, who is a pretty good guy for a dyed-in-the-wool HDS cheerleader, and I have been videoing back and forth about HBP and 3PAR's thin provisioning differences.  I seem to recall him saying that you could setup an HDS array with a single pool.  Really Nigel - would that be s serious recommended best practice? All data stored in one RAID level?

Tony Asaro, in his blog,  quoted Nigel as saying:

For a start it maps perfectly with the internal workings of the USP V and VM.

Which was my point - Hitachi's engineer's did it to make it easier for themselves as opposed to fitting it to customer requirements.  Which leads me to Nigel's metadata fixation where he assumes that all metadata processes obey the same immutable rules of coding. They don't. That's because processes that are core design concepts usually are more efficient than bolt-on afterthoughts.  

Allegro - crushing it in eastern Europe

Allegro is an online auction company in Poland and they are dominating the market in eastern Europe.  Four guys from their technology team came to 3PAR HQ last week on a visit to several of their strategic vendors and they were nice enough to take the time to let me interview them.  They take advantage of lots of open source software, and believe in running their operations on robust, flexible and scalable products from companies like 3PAR, Brocade and Cisco.  The audio for this video is pretty soft, so you will probably need to crank up the volume to hear it.

Yes my dear, thin provisioning allocation size matters

Why use thin provisioning technology if it turns out that it's not efficient?  That's the question for Hitachi's Dynamic Provisioning, with its 42 MB allocation unit size.

The allocation unit is the amount of physical storage that is commited to a volume when new data is written to disk.  Allocating an amount of storage that is close in size to a typical write means that utilization levels can remain high, giving customers the biggest bang for the buck.  That's why our allocation units at 3PAR are 16 KB. 

It's hard to imagine what Hitachi was thinking when they came up with 42 MB allocation units. The amount of physical storage commited for each new write is in the range of 5000 times more than what is needed for a typical 8KB write. Yikes.  Of course many applications write more than 8KB at a time, but how many come close to 42 MB?  (almost none).  The whole thing is just bizarre. 

There are some hints about why Hitachi did it this way.  In a recent comment on my blog, Hu Yoshida mentioned the management burden to the system of tracking small allocation units.  Apparently Hitachi's engineer's didn't get the requirements quite right on this one and decided to leverage the customer's experience against their develoment effort. 

Oops, correcting my HDS bloat shrink blog

I'm probably not alone when I say that I figured HDS' zero page reclaim was something more than it actually is.  After I posted my bloat/shrink video a couple days ago, Hu Yoshida at HDS posted a pretty clear entry explaining that it is a fat to thin migration function. My apologies for not getting it right - I should have - and so I try in this video below, once again, to explain what it is.

Zero page reclaim has been one of the stranger announcements this year - and it certainly doesn't top Storage Anarchist's announcement coup of IBM's XIV last year, but if there were awards, for this sort of thing there might be a category for zero page reclaim this year.

Crazed night for Steering Wheel Cam on the Solstice!

Blog readers are warned. This is a Steering Wheel Cam Society of America video and has nothing whatsoever to do with storage.

Equinoxes are nowhere when it comes to SWCSA activity. Check out this fresh video that includes the first ever SWC-PM as well as a great chase with a Vega and a Ferrari and a Prius mixing it up.

HDS' catastrophic storage management

Catastrophe theory attempts to explain how seemingly small, incremental changes to systems result in catastrophic results - such as bridge collapses. Sometimes it involves oscillating or resonating behaviors that get out of control.

When HDS released their version of dynamic provisioning, they created a system that can grow in ways that can cause problems for customers.  The allocation unit for dynamic provisioning is large compared to other thin technologies - and when lots of host systems start writing to unallocated block storage, the amount of available, physical storage needed to supply all those allocations can spike quickly. Can it become a storage catastrophe?  I don't know, but it certainly is the poster child for thin provisioning out-of-disk-space concerns.

In order to fix the over-allocation of storage by dynamic provisioning, they (sort of) released their zero page reclaim feature back in February to get back some of the allocation overkill. It's not exactly two wrongs making a right, but zero page reclaim is simply a bug fix for sloppy, bloated dynamic provisioning. It's interesting that several months after making the functionality available they announced it this week as if its something new.  I guess you can do that if you keep it swept under the rug well enough.

Reclaim technology is going to be a very big deal in the storage industry, but it will work much better when it is integrated with efficient thin technologies, such as those developed by 3PAR, to create a consistent, well-behaved, predictable environment - as opposed to one that requires customers to manage unpredictable allocation storms.

The long term issues with dedupe technology

Digital archivists struggle with the question of whether there will be equipment available to read data from media that was many years before. It's not a simple matter of keeping devices for decades because all interfaces, including things like computer I/O buses, network interfaces and even power cables need to be preserved.

Carter George at Ocarina has a good post today discussing what some of the implications of dedupe technology are for archival storage. He touches on software issues, metadata and legal topics that need to be considered.  If you have an interest in using dedupe for long term archival you probably need to be paying attention to what Carter is talking about here.

 

An interview with Frey Kuo from TheLadders.com

TheLadders.com, is a job board for people earning more than $100,000 per year. I recently spoke with Frey Kuo, Director of Information Technology & Operations at TheLadders.com about the technology they use and how 3PAR storage helps them manage the "hyper growth" they have been experiencing. 

Their "Chairs" Super Bowl ad is pretty clever. You can see the whole thing and other ads of theirs are their  Youtube channel.  Check them out.