Every year DCIG scores and ranks over 50 midrange arrays to help storage buyers make an educated decision on future purchases. Like most of these reports, it takes months to put together and by the time the report is released, the information is stale and out of date. I noticed in this year’s report they XiV gen3 system was listed as the number 6 system behind some of the other vendors that were ranked with a higher score. I decided to dig in and see what was the difference between the number 6 and the number 1 array.
The fist thing I noticed is the ranking on the XiV was based on some old/incorrect data. Here is a snapshot of the report with red circles on things that are not correct:
A couple of things we should point is the support for SSD drives. IBM XiV started support for the multi-level cell drives to enhance its read cache up to 6TB on a full populated system. This increases performance by 3X in most cases. Other options listed like mirroring and snapshot licenses included have been part of the system since the Gen2 days.
The XiV system also supports VASA, that crazy acronym inside of another acronym. The VMWare API for Storage Awareness allows for automation of storage operations and monitor storage alerts. Most storage vendors have come to the same conclusion that IBM has that you have support VASA if you are going to be part of the future.
As you prepare to sit down and start to decide which here are a few things to consider when looking at the XiV system:
1. Management is close to zero. This system is not only easy to deploy but it self tunes itself. The problems with other traditional systems like hot spots or provisioning is made easier with XiV technology.
2. All features are included. No need to worry if you bought the right licenses as all of them are included in the price.
3. XiV is true grid based storage. You really have to compare apples to apples and look under the covers at other storage systems. They may claim some type of grid architecture but in reality they are still using active / active pairs instead of 15 modules all working together on a infiband backbone.
While this is no dig on the DCIG team, it is a little misleading potential customers. I spoke with the analyst that puts these together and he admitted that it was done back in the September time frame and may not represent the true feature and functionality that IBM offers today. I also learned they are working on a more interactive report that can be updated more regularly.
The differences in what they published and what is offered today would more than surpass some of the other storage arrays listed ahead of the XiV. I also would like to see them consider the XiV more of a enterprise array and not so much of the midrange but that’s another blog article entirely.
Post from Roger Luethy:
This paper highlights the importance of mirroring as a data protection strategy to minimize risk of data and system unavailability and the advantages of IBM® XIV® Storage System asynchronous mirroring. It covers the system’s essential mirroring solution characteristics and organizational mirroring requirements that ensure business continuity. While this paper touches on the value of synchronous mirroring in certain situations, its primary focus is asynchronous mirroring.
Reading this paper will give you a clear understanding of effective enterprise mirroring implementations and the IBM XIV Storage System series solution, which offers a comprehensive, successful mirroring strategy for today and the future.
One thing that has gotten a lot of attention in the last 6 months is how much cache you can put into a solution. Fusion IO has caught fire with its cache cards that you put into the host. Texas Memory and Violin have solid state arrays that can help accelerate your SAN environment. But those only mask the real problem.
Most of the time people are not saturating their 8GB FC link or even their 10GB CNA link to between their host system and their storage. So network is usually not that big of a problem (if configured correctly of course).
The cache cards that are installed in the host systems do offload some of the reads and writes that normally go to the storage array but unless the cache is shared, then you can get into situations where you are keeping multiple copies of the same data in multiple systems. This is effective for each host but not for the entire data center.
Then there is the all mighty “lets put faster disk in between the real disk and the hosts” solution that has been around since we started getting off Ultra Wide SCSI disk arrays. This does again solve the issue of performance but becomes either an one off solution or involves time to get up and running and only benefits the data that lands on those disks.
At IBM, the XIV Storage System has been evolving since we purchased the technology a few years ago. When I first learned of the system I thought the information was wrong, no way could a box that was just a bunch of servers with no raid out perform some of the tried and tested systems not only at IBM but in the storage market. After doing the research and talking to customers that run XIV in their datacenter, I was starting to believe. Was I drinking the Kool-Aid (no this is not a Netapp Blog) or was this a real shift in the storage technology?
Fast forward a couple of years and now IBM is deploying the third generation of XIV. One of the biggest factors way customers switch to XIV is how it lowers the amount of administration overhead. This shows up when other vendors are trying to put so many features and functionality into their product but they are missing the fact that most people want it to be easier. As their data footprint grows, they know the amount of time to keep up with were data lives or the time it takes to provision a lun will grow exponentially.
It was only after talking with a customer who previously not purchased IBM storage and hearing their story of how much work went into keeping up with the day to day running of the storage that I understood that the XIV was more than just a pretty face/GUI.
Today, IBM announced the addition of solid state drives to its XIV system. But wait, doesn’t XIV only use near line SAS drives and touts the whole ‘no tiers’ strategy? Correct. The XIV system is adding these SSD drives not for another tier but to increase the amount of cache available to the entire storage array (unless you thing cache is really tier 0, then ok whatever.). This improves performance of the entire array three times the original XIV GEN3 SPC-2/E benchmark. But wait, there’s more!
Because XIV spreads the load across all of the modules in the array, all of the data that is stored gets a bigger benefit than just adding cache to a host. The XIV can now also exclude certain volumes from benefitting from the improved performance allowing you to maintain efficient use of the SSD technology. The XIV executes an intelligent prefetch of data that is triggered when random reads are sensed. For random operations, XIV SSD cache will prefetch pages to increase the cache hit ratio. With XIV, SSD hotspots are monitored and managed by the storage system. Data placement algorithms from IBM Research are designed to improve wear leveling and optimize performance. XIV SSD Caching is the first commercial implementation of this IBM research project. The future of storage is going to change were customers react to requirements, projects and deployments that are easier to manage on a larger scale.A storage system like XIV that drives the tangible benefits of easy to use with the intangibles (seeing your kids on the weekends instead of doing a data migration on a volume that is out of space and you can’t add space on the fly or even roll back to a snapshot cause if you turn them on the box will melt) shows how IBM is ahead of the game. For more information about XIV and the 3x improvement go here
Right off the top, I don’t usually like promoting things with an “i” in front of the name but I have seen a little glimmer of light. This year IBM released an application (app) for monitoring and administrating the XiV system from an iPad. I quickly dismissed it as something that is nice to have but not a necessity.
But the more I thought about how the XiV system is designed to have an easy to use interface and one of the selling points of all of the Apple products is the ease of use, I can see why people would want an app like this. This generation of engineers/administrators are always looking for the cool part of the box. This allows them to be a little less attached to their laptop or cubicle so when someone asks for LUN or a status report on the performance they can pull that information up while sitting in the coffee shop.
The app can be run in production mode or a demo mode which also helps us IBMers showing it to other clients. The Demo mode allows you to see how the app works with out connecting to a real XiV. Pretty cool.
After securely logging into a real XiV system you can see performance of the system from both the volume and host perceptive. By swiping the screen (like turning a page) you can go back and forth the screens. Here are a couple of screens shots of what you would see on your iPad.
The only two things I have asked the XiV software team is how can use this to create an app that will also monitor SVC/V7000U/DS8000 as they all have the same interface. The second is to port this over for Android so I can run it from my droid tablet!