Speaking of SSDs (with poll)

StorageIO Industry trends and perspectives image

In the spirit of solid state devices (SSD) including DRAM and nand flash, not to mention emerging phase chance memory (PCM) among others that help to boost productivity and cut latency, here are a couple of quick notes and links.

Here are a some more pieces to have a quick look at:
SSD & Real Estate: Location, Location, Location matters
SSD Is in Your Future: Where, When & With What Are the Questions
Storage & IO trends for 2013 and beyond

SSD, flash and DRAM, DejaVu or something new?

Storage I/O ssd timeline image

Is SSD only for performance?
Have SSDs been unsuccessful with storage arrays (with poll)?
End the Hardware Numbers Game

Desum poll planned SSD use image
Image via 21cit (desum): The SSD hardware numbers game

What’s your take on SSD in storage arrays, cast your vote and see results here.

Also check out here what Micron has in mind with merging nand flash with the DDR4 (e.g. DRAM socket) memory bus for servers in a year or two.

Ok, nuff said.

Cheers gs

Greg Schulz – Author Cloud and Virtual Data Storage Networking (CRC Press, 2011), The Green and Virtual Data Center (CRC Press, 2009), and Resilient Storage Networks (Elsevier, 2004)

twitter @storageio

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2024 Server StorageIO and UnlimitedIO LLC All Rights Reserved

Are large storage arrays dead at the hands of SSD?

Storage I/O trends

An industry trends and perspective.

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Are large storage arrays dead at the hands of SSD? Short answer NO not yet.
There is still a place for traditional storage arrays or appliances particular those with extensive features, functionality and reliability availability serviceability (RAS). In other words, there is still a place for large (and small) storage arrays or appliances including those with SSDs.

Is there a place for newer flash SSD storage systems, appliances and architectures? Yes
Similar to how there is a place for traditional midrange storage arrays or appliances have found their roles vs. traditional higher end so-called enterprise arrays. Think as an example  EMC CLARiiON/VNX or HP EVA/P6000 or HDS AMS/HUS or NetApp FAS or IBM DS5000 or IBM V7000 among others vs. EMC Symmetrix/DMX/VMAX or HP P10000/3Par or HDS VSP/USP or IBM DS8000. In addition to traditional enterprise or high-end storage systems and midrange also known as modular, there are also specialized appliances or targets such as for backup/restore and archiving. Also do not forget the IO performance SSD appliances like those from TMS among others that have been around for a while.

Is the role of large storage systems changing or evolving? Yes
Given their scale and ability to do large amounts of work in a dense footprint, for some the role of these systems is still mission critical tier 1 application and data support. For other environments, their role continues to evolve being used for high-density tier 2 bulk or even near-line storage for on-line access at scale.

Storage I/O trends

Does this mean there is completion between the old and new systems? Yes
In some circumstances as we have seen already with SSD solutions. Some will place as competing or replacements while others as complementing. For example in the PCIe flash SSD card segment EMC VFCache is positioned is complementing Dell, EMC, HDS, HP, IBM, NetApp, Oracle or others storage vs. FusionIO who positions as a replacement for the above and others. Another scenario is how some SSD vendors have and continue to position their all-flash SSD arrays using either drives or PCIe cards to complement and coexist with other storage systems in an environment (e.g. data center level tiering) vs. as a replacement. Also keep in mind SSD solutions that also support a mix of flash devices and traditional HDDs for capacity and cost savings or cloud access in the same solution.

Does this mean that the industry has adopted all SSD appliances as the state of art?
Avoid confusing industry adoption or talk with industry and customer deployment. They are similar, however one is focused on what the industry talks about or discusses as state of art or the future while the other is what customers are doing. Certainly some of the new flash SSD appliance and storage startups such as Solidfire, Nexgen, Violin, Whiptail or veteran TMS among others have promising futures, some of which may actually be in play with the current SSD market shakeout and consolidation.

Does that mean everybody is going SSD?
SSD customer adoption and deployment continues to grow, however so too does the deployment of high-capacity HDDs.

Storage I/O trends

Do SSDs need HDDs, do HDDs need SSDs? Yes
Granted there are environments where needs can be addressed by all of one or the other. However at least near term, there is a very strong market for tiering and mix of SSD, some fast HDDs and lots of high-capacity HDDs to meet various needs including performance, availability, capacity, energy and economics. After all, there is no such thing, as a data or information recession yet budgets are tight or being reduced. Likewise, people and data are living longer.

What does this mean?
If there, were no such thing as a data recession and budgets a non-issue, perhaps everything could move to all flash SSD storage systems. However, we also know that people and data are living longer along with changing data life-cycle patterns. There is also the need for performance to close the traditional data center IO performance to space capacity gap and bottlenecks as well as store and keep data longer.

There will continue to be a need for a mix of high-capacity and high performance. More IO will continue to gravitate towards the IO appliances, however more data will settle in for longer-term retention and continued access as data life-cycle continue to evolve. Watch for more SSD and cache in the large systems, along with higher density SAS-NL (SAS Near Line e.g. high capacity) type drives appearing in those systems.

If you like new shiny new toys or technology (SNTs) to buy, sell or talk about, there will be plenty of those to continue industry adoption while for those who are focused on industry deployment, there will be a mix of new, and continued evolution for implementation.

Related links
Industry adoption vs. industry deployment, is there a difference?

Industry trend: People plus data are aging and living longer

No Such Thing as an Information Recession

Changing Lifecycles & Data Footprint Reduction
What is the best kind of IO? The one you do not have to do
Is SSD dead? No, however some vendors might be
Speaking of speeding up business with SSD storage
Are Hard Disk Drives (HDD’s) getting too big?
IT and storage economics 101, supply and demand
Has SSD put Hard Disk Drives (HDD’s) On Endangered Species List?
Why SSD based arrays and storage appliances can be a good idea (Part I)
Researchers and marketers don’t agree on future of nand flash SSD
EMC VFCache respinning SSD and intelligent caching (Part I)
SSD options for Virtual (and Physical) Environments Part I: Spinning up to speed on SSD

Ok, nuff said for now

Cheers Gs

Greg Schulz – Author Cloud and Virtual Data Storage Networking (CRC Press, 2011), The Green and Virtual Data Center (CRC Press, 2009), and Resilient Storage Networks (Elsevier, 2004)

twitter @storageio

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2012 StorageIO and UnlimitedIO All Rights Reserved

More Storage IO momentus HHDD and SSD moments part II

This follows the first of a two-part series on my latest experiences with Hybrid Hard Disk Drives (HHDD’s) and Solid State Devices (SSD’s). In my ongoing last momentus moment post I discussed what I have done with HHDD’s and setting the stage for expanded SSD use. I have the newer HHDD’s, e.g. Seagate Momentus XT II 750GB (8GB SLC nand flash) installed and have since bought another from Amazon as well as having some of the older 500GB (4GB SLC nand flash) in various systems. Those are all functioning great, however still waiting and looking forward to the rumored firmware enhancements to boost write capabilities.

This brings me up to the latest momentus moment which now includes SSD’s.

Well its two years later and I now have a 256GB (usable capacity is lower) Samsung SSD that I bought from Amazon.com and installed in one of my laptops and just as when I made the first switch to HHDD’s, I also have a backup copy/clone to fall back to in case of emergency.

Was it worth the wait? Yes, particularly using the HHDD’s to bridge the gap and enable some productivity gain which more than paid for them based on some different projects. I’m already seeing productivity improvements that will make future upgrades more easy to justify (to myself).

I deviated from my strategy a bit and installed the SSD about six months earlier than I was planning to do so because of a physical barrier. That physical barrier was my new traveling laptop only accepts 7mm height 2.5 inch small form factor devices and the 750GB HHDD that I had planned on installing was 2.5mm to thick which pushed up the SSD installation.

What will become of the 750GB HHDD? Its being redeployed to help speed up file serving, backups and other functions.

Will I replace the HHDD’s in my other workstations and laptops now with SSD’s? Across the board no, not yet, however there is one other system that is a prime candidate to maybe upgrade in a month or two (maybe less).

Will I stick with the Samsung SSD’s or look at other options? I’m keeping my options open and using this as a gauge to test and compare other options in a real world working environment as opposed to a lab bench test simulation. In other words, taking the next step past the lab test and product reviews, gaining comfort and confidence and then trying out with real use activity.

What will happen in the future as I install more SSD’s and have surplus HHDD’s? Redeployed them of course into file or NAS servers, backup targets that in turn will replace HDD’s that will either get retired, or redeployed to replace older, smaller capacity, higher cost to handle HDD’s used for offsite protection.

I tried using the software that came with the SSD to do the cloning and should have known better, however wanted to see what the latest version of ghost was like (it was a waste of time to be polite). Instead I used Seagate Discwizard (aka Acronis) which requires at least one Seagate product (source or target) for cloning.

Cloning from the Seagate HHDD that have been previously cloned from the Hitachi HDD that came with the laptop, was a none issue. However, I wanted to see what would happen if I attached the Samsung SSD to the Seagate Goflex cable and clone directly from the Hitachi HDD, it worked. Hence another reason to have some of the Seagate Goflex cables (USB and eSATA) like the ones I bought at Amazon.com around in your toolbox.

While I do not have concrete empirical numbers to share, cloning from a HDD to a SSD is shall we say fast, however, what’s really fun to watch is cloning from a HHDD to a SSD using an eSata (GoFlex) connector adapter. The reason I say that it is fun is that you don’t have to sit and wait for hours, it’s not minutes to move 100s of GBs, however you can very much see the progress bar move at a good pace.

Also, I put the HHDD on an eSata port and try that out as a backup or data dump target if you have the need for speed, capacity and cost effectiveness, yes its fast, has lots of capacity and so forth. Now if Seagate and Synology or EMC Iomega would get their acts together and add support for the HHDD’s in those different unified SMB and SOHO NAS solutions, that would be way cool.

Will I be racing to put SSD’s in my other laptops or workstations soon? Probably not as there are things in the works and working their way into and through the market place that I wanted to wait for, and thus will wait for now, that is unless a more interesting opportunity pops up.

Related links on SDD, HHDD and HDD
More Storage IO momentus HHDD and SSD moments part I
More Storage IO momentus HHDD and SSD moments part II
IO IO it is off to Storage and IO metrics we go
New Seagate Momentus XT Hybrid drive (SSD and HDD)
Other Momentus moments posts here here, here, here and here
SSD and Storage System Performance
Speaking of speeding up business with SSD storage
Are Hard Disk Drives (HDD’s) getting too big?
Has SSD put Hard Disk Drives (HDD’s) On Endangered Species List?
Why SSD based arrays and storage appliances can be a good idea (Part I)
Why SSD based arrays and storage appliances can be a good idea (Part II)
IT and storage economics 101, supply and demand
Researchers and marketers dont agree on future of nand flash SSD
EMC VFCache respinning SSD and intelligent caching (Part I)
EMC VFCache respinning SSD and intelligent caching (Part II)
SSD options for Virtual (and Physical) Environments Part I: Spinning up to speed on SSD
SSD options for Virtual (and Physical) Environments Part II: The call to duty, SSD endurance
SSD options for Virtual (and Physical) Environments Part III: What type of SSD is best for you?
SSD options for Virtual (and Physical) Environments Part IV: What type of SSD is best for your needs

Ok, nuff said for now.

Cheers Gs

Greg Schulz – Author Cloud and Virtual Data Storage Networking (CRC Press, 2011), The Green and Virtual Data Center (CRC Press, 2009), and Resilient Storage Networks (Elsevier, 2004)

twitter @storageio

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2012 StorageIO and UnlimitedIO All Rights Reserved

More Storage IO momentus HHDD and SSD moments part I

This is the first of a two part series on my latest experiences with HHDD and SSD’s

About two years ago I wanted to start installing solid state devices (SSD’s) into my workstations and laptops. Like many others, I found the expensive price for the limited capacity gains of the then generation SSD’s did not make for a good business decision based on my needs. Don’t get me wrong, I have been a huge fan of SSD for decades as an IT user, vendor, analysts, consultant and consumer and still am. In fact I have some SSD’s used for different purposes as well as many Hard Disk Drives (HDD) and Hybrid Hard Disk Drives (HHDD’s). Almost two years ago when I first tested the HHDD’s, I did an first post in this ongoing series and this two-part post is part of that string of experiences observed evolving from HDD’s to HHDD’s to SSD’s


Image courtesy of Seagate.com

As a refresher, HHDD’s like the Seagate Momentus XT combine a traditional 7,200 RPM 2.5 inch 500GB or 750GB HDD with an integrated single level cell (SLC) nand flash SSD within the actual device. The SSD in the HHDD’s is part of the HDD’s controller complementing the existing DRAM buffer by adding 4GB (500GB models) or 8GB (750GB models) of fast nand flash SSD cache. This means that no external special controller, adapter, data movement or migration software are required to get the performance boost over a traditional HDD and the capacity above a SSD at an affordable cost. In other words, the HHDD’s bridge the gap between those who need large capacity and some performance increases, without having to spend a lot on a lower capacity SSD.

However based on my needs or business requirements two years ago I found the justification to get all the extra performance of  SSD not quite there when. Back two years ago my thinking was that it would be about two maybe three years before the right point for a mix of performance, availability (or reliability e.g. duty cycles), capacity and economics aligned.

Note that this was based on my specific needs and requirements as opposed to my wants or wishes (I wanted SSD back then, however my budget needed to go elsewhere). My requirements and performance needs are probably not the same as yours or others might be. I also wanted to see the incremental technology, product and integration improvements ranging from duty cycle or program/erase cycles (P/E) with newer firmware and flash translation layers (FTLs) among other things. Particularly with multilevel cell (MLC) or enhanced multilevel cell (eMLC) which helps bring the cost down while boosting the capacity, I’m seeing enough to have more confidence in those devices. Note that for the past couple of years I have used single level cell (SLC) nand flash SSD technology in my HHDD’s, the same SSD flash technology that has been found in enterprise class storage.

While I wanted SSD’s two years ago in my laptops and workstations to improve productivity which involves a lot of content creation in addition to consumption, however as mentioned above, there were barriers. So instead of sitting on the sidelines, waiting for SSD’s to either become lower cost, or more capacity for a given cost, or wishing somebody would send me some free stuff (that may or may not have worked), I took a different route. That route was to try the HHDD’s such as Seagate Momentus XT.

Disclosure: Seagate sent me my first HHDD for first testing and verifications before buying several more from Amazon.com and installing them in all laptops, workstations and a server (not all servers have the HHDD’s, or at least yet).

The main reason I went with the HHDD’s two years ago and continue to use them today is to bridge the gap and gain some benefit vs. waiting and wishing and talking about what SSD’s would enable me to do in the future while missing out on productivity enhancements.

The HHDD’s also appealed to me in that my laptops are space constrained for putting two drives and playing the hybrid configuration game of installing both a small SSD and HDD and migrating data back and forth. Sure I could do that for in the office or carry an extra external device around however been there, done that in the past and want to move away from those types of models where possible.

Related links on SDD, HHDD and HDD
More Storage IO momentus HHDD and SSD moments part I
More Storage IO momentus HHDD and SSD moments part II
IO IO it is off to Storage and IO metrics we go
New Seagate Momentus XT Hybrid drive (SSD and HDD)
Other Momentus moments posts here here, here, here and here
SSD and Storage System Performance
Speaking of speeding up business with SSD storage
Are Hard Disk Drives (HDD’s) getting too big?
Has SSD put Hard Disk Drives (HDD’s) On Endangered Species List?
Why SSD based arrays and storage appliances can be a good idea (Part I)
Why SSD based arrays and storage appliances can be a good idea (Part II)
IT and storage economics 101, supply and demand
Researchers and marketers dont agree on future of nand flash SSD
EMC VFCache respinning SSD and intelligent caching (Part I)
EMC VFCache respinning SSD and intelligent caching (Part II)
SSD options for Virtual (and Physical) Environments Part I: Spinning up to speed on SSD
SSD options for Virtual (and Physical) Environments Part II: The call to duty, SSD endurance
SSD options for Virtual (and Physical) Environments Part III: What type of SSD is best for you?
SSD options for Virtual (and Physical) Environments Part IV: What type of SSD is best for your needs

Ok, nuff said for now, lets resume this discussion in part II.

Cheers Gs

Greg Schulz – Author Cloud and Virtual Data Storage Networking (CRC Press, 2011), The Green and Virtual Data Center (CRC Press, 2009), and Resilient Storage Networks (Elsevier, 2004)

twitter @storageio

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2012 StorageIO and UnlimitedIO All Rights Reserved

Why SSD based arrays and storage appliances can be a good idea (Part II)

This is the second of a two-part post about why storage arrays and appliances with SSD drives can be a good idea, here is link to the first post.

So again, why would putting drive form factors SSDs be a bad idea for existing storage systems, arrays and appliances?

Benefits of SSD drive in storage systems, arrays and appliances:

  • Familiarity with customers who buy and use these devices
  • Reduces time to market enabling customers to innovate via deployment
  • Establish comfort and confidence with SSD technology for customers
  • Investment protection of currently installed technology (hardware and software)
  • Interoperability with existing interfaces, infrastructure, tools and policies
  • Reliability, availability and serviceability (RAS) depending on vendor implementation
  • Features and functionality (replicate, snapshot, policy, tiering, application integration)
  • Known entity in terms of hardware, software, firmware and microcode (good or bad)
  • Share SSD technology across more servers or accessing applications
  • Good performance assuming no controller, hardware or software bottlenecks
  • Wear leveling and other SSD flash management if implemented
  • Can end performance bottlenecks if backend (drives) are a problem
  • Coexist or complemented with server-based SSD caching

Note, the mere presence of SSD drives in a storage system, array or appliance will not guarantee or enable the above items to be enabled, nor to their full potential. Different vendors and products will implement to various degrees of extensibility SSD drive support, so look beyond the check box of feature, functionality. Dig in and understand how extensive and robust the SSD implementation is to meet your specific requirements.

Caveats of SSD drives in storage systems, arrays and appliances:

  • May not use full performance potential of nand flash SLC technology
  • Latency can be an issue for those who need extreme speed or performance
  • May not be the most innovative newest technology on the block
  • Fun for startup vendors, marketers and their fans to poke fun at
  • Not all vendors add value or optimization for endurance of drive SSD
  • Seen as not being technology advanced vs. legacy or mature systems

Note that different vendors will have various performance characteristics, some good for IOPs, others for bandwidth or throughput while others for latency or capacity. Look at different products to see how they will vary to meet your particular needs.

Cost comparisons are tricky. SSD in HDD form factors certainly cost more than raw flash dies, however PCIe cards and FTL (flash translation layer) controllers also cost more than flash chips by themselves. In other words, apples to apples comparisons are needed. In the future, ideally the baseboard or motherboard vendors will revise the layout to support nand flash (or its replacement) with DRAM DIMM type modules along with associated FTL and BIOS to handle the flash program/erase cycles (P/E) and wear leveling management, something that DRAM does not have to encounter. While that provides great location or locality of reference (figure 1), it is also a more complex approach that takes time and industry cooperation.

Locality of reference for memory and storage
Figure 1: Locality of reference for memory and storage

Certainly, for best performance, just like realty location matters and thus locality of reference comes into play. That is put the data as close to the server as possible, however when sharing is needed, then a different approach or a companion technique is required.

Here are some general thoughts about SSD:

  • Some customers and organizations get the value and role of SSD
  • Some see where SSD can replace HDD, others see where it compliments
  • Yet others are seeing the potential, however are moving cautiously
  • For many environments better than current performance is good enough
  • Environments with the need for speed need every bit of performance they can get
  • Storage systems and arrays or appliances continue to evolve including the media they use
  • Simply looking at how some storage arrays, systems and appliances have evolved, you can get an idea on how they might look in the future which could include not only SAS as a backend or target, also PCIe. After all, it was not that long ago where backend drive connections went from propriety to open parallel SCSI or SSA to Fibre Channel loop (or switched) to SAS.
  • Engineers and marketers tend to gravitate to newer products nand technology, which is good, as we need continued innovation on that front.
  • Customers and business people tend to gravitate towards deriving greatest value out of what is there for as long as possible.
  • Of course, both of the latter two points are not always the case and can be flip flopped.
  • Ultrahigh end environments and corner case applications will continue to push the limits and are target markets for some of the newer products and vendors.
  • Likewise, enterprise, mid market and other mainstream environments (outside of their corner case scenarios) will continue to push known technology to its limits as long as they can derive some business benefit value.

While not perfect, SSD in a HDD form factor with a SAS or SATA interface properly integrated by vendors into storage systems (or arrays or appliances) are a good fit for many environments today. Likewise, for some environments, new from the ground up SSD based solutions that leverage flash DIMM or daughter cards or PCIe flash cards are a fit. So to are PCIe flash cards either as a target, or as cache to complement storage system (arrays and appliances). Certainly, drive slots in arrays take up space for SSD, however so to does occupying PCIe space particularly in high density servers that require every available socket and slot for compute and DRAM memory. Thus, there are pros and cons, features and benefits of various approaches and which is best will depend on your needs and perhaps preferences, which may or may not be binary.

I agree that for some applications and solutions, non drive form factor SSD make sense while in others, compatibility has its benefits. Yet in other situations nand flash such as SLC combined with HDD and DRAM tightly integrated such as in my Momentus XT HHDD is good for laptops, however probably not a good fit for enterprise yet. Thus, SSD options and placements are not binary, of course, sometimes opinions and perspectives will be.

For some situations PCIe, based cards in servers or appliances make sense, either as a target or as cache. Likewise for other scenarios drive format SSD make sense in servers and storage systems, appliances, arrays or other solutions. Thus while all of those approaches are used for storing binary digital data, the solutions of what to use when and where often will not be binary, that is unless your approach is to use one tool or technique for everything.

Here are some related links to learn more about SSD, where and when to use what:
Why SSD based arrays and storage appliances can be a good idea (Part I)
IT and storage economics 101, supply and demand
Researchers and marketers dont agree on future of nand flash SSD
Speaking of speeding up business with SSD storage
EMC VFCache respinning SSD and intelligent caching (Part I)
EMC VFCache respinning SSD and intelligent caching (Part II)
SSD options for Virtual (and Physical) Environments: Part I Spinning up to speed on SSD
SSD options for Virtual (and Physical) Environments, Part II: The call to duty, SSD endurance
SSD options for Virtual (and Physical) Environments Part III: What type of SSD is best for you?

Ok, nuff said for now.

Cheers gs

Greg Schulz – Author Cloud and Virtual Data Storage Networking (CRC Press, 2011), The Green and Virtual Data Center (CRC Press, 2009), and Resilient Storage Networks (Elsevier, 2004)

twitter @storageio

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2012 StorageIO and UnlimitedIO All Rights Reserved

Why SSD based arrays and storage appliances can be a good idea (Part I)

This is the first of a two-part series, you can read part II here.

Robin Harris (aka @storagemojo) recently in a blog post asks a question and thinks solid state devices (SSDs) using SAS or SATA interface in traditional hard disk drive (HDD) form factors are a bad idea in storage arrays (e.g. storage systems or appliances). My opinion is that as with many things about storing, processing or moving binary digital data (e.g. 1s and 0s) the answer is not always clear. That is there may not be a right or wrong answer instead it depends on the situation, use or perhaps abuse scenario. For some applications or vendors, adding SSD packaged in HDD form factors to existing storage systems, arrays and appliances makes perfect sense, likewise for others it does not, thus it depends (more on that in a bit). While we are talking about SSD, Ed Haletky (aka @texiwill) recently asked a related question of Fix the App or Add Hardware, which could easily be morphed into a discussion of Fix the SSD, or Add Hardware. Hmmm, maybe a future post idea exists there.

Lets take a step back for a moment and look at the bigger picture of what prompts the question of what type of SSD to use where and when along as well as why various vendors want you to look at things a particular way. There are many options for using SSD that is packaged in various ways to meet diverse needs including here and here (see figure 1).

Various SSD packaging options
Figure 1: Various packaging and deployment options for SSD

The growing number of startup and established vendors with SSD enabled storage solutions vying to win your hearts, minds and budget is looking like the annual NCAA basketball tournament (aka March Madness and march metrics here and here). Some of vendors have or are adding SSD with SAS or SATA interfaces that plug into existing enclosures (drive slots). These SSDs have the same form factor of a 2.5 inch small form factor (SFF) or 3.5 inch HDDs with a SAS or SATA interface for physical and connectivity interoperability. Other vendors have added PCIe based SSD cards to their storage systems or appliances as a cache (read or read and write) or a target device similar to how these cards are installed in servers.

Simply adding SSD either in a drive form factor or as a PCIe card to a storage system or appliance is only part of a solution. Sure, the hardware should be faster than a traditional spinning HDD based solution. However, what differentiates the various approaches and solutions is what is done with the storage systems or appliances software (aka operating system, storage applications, management, firmware or micro code).

So are SSD based storage systems, arrays and appliances a bad idea?

If you are a startup or established vendor able to start from scratch with a clean sheet design not having to worry about interoperability and customer investment protection (technology, people skills, software tools, etc), then you would want to do something different. For example, leverage off the shelf components such as a PCIe flash SSD card in an industry standard server combined with your software for a solution. You could also use extra DRAM memory in those servers combined with PCIe flash SSD cards perhaps even with embedded HDDs for a backing or preservation medium.

Other approaches might use a mix of DRAM, PCIe flash cards, as either a cache or target combined with some drive form factor SSDs. In other words, there is no right or wrong approach; sure, there are different technical merits that have advantages for various applications or environments. Likewise, people have preferences particular for technology focused who tend to like one approach vs. another. Thus, we have many options to leverage, use or abuse.

In his post, Robin asks a good question of if nand flash SSD were being put into a new storage system, why not use the PCIe backplane vs. using nand flash on DIMM vs. using drive formats, all of which are different packaging options (Figure 1). Some startups have gone the all backplane approach, some have gone with the drive form factor, some have gone with a mix and some even using HDDs in the background. Likewise some traditional storage system and array vendors who support a mix of SSD and HDD drive form factor devices also leverage PCIe cards, either as a server-based cache (e.g. EMC VFCahe) or installed as a performance accelerator module (e.g. NetApp PAM) in their appliances.

While most vendors who put SSD drive form factor drives into their storage systems or appliances (or serves for that matter) use them as data targets for creating LUNs or file systems, others use them for internal functionality. By internal functionality I mean instead of the SSD appearing as another drive or target, they are used exclusively by the storage system or appliance for caching or similar purposes. On storage systems, this can be to increase the size of persistent cache such as EMC on the CLARiiON and VNX (e.g. FAST Cache). Another use is on backup or dedupe target appliances where SSDs are used to store dictionary, index or meta data repositories as opposed to being a general data pool.

Part two of this post looks at the benefits and caveats of SSD in storage arrays.

Here are some related links to learn more about SSD, where and when to use what:
Why SSD based arrays and storage appliances can be a good idea (Part II)
IT and storage economics 101, supply and demand
Researchers and marketers don’t agree on future of nand flash SSD
Speaking of speeding up business with SSD storage
EMC VFCache respinning SSD and intelligent caching (Part I)
EMC VFCache respinning SSD and intelligent caching (Part II)
SSD options for Virtual (and Physical) Environments: Part I Spinning up to speed on SSD
SSD options for Virtual (and Physical) Environments, Part II: The call to duty, SSD endurance
SSD options for Virtual (and Physical) Environments Part III: What type of SSD is best for you?

Ok, nuff said for now, check part II.

Cheers gs

Greg Schulz – Author Cloud and Virtual Data Storage Networking (CRC Press, 2011), The Green and Virtual Data Center (CRC Press, 2009), and Resilient Storage Networks (Elsevier, 2004)

twitter @storageio

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2012 StorageIO and UnlimitedIO All Rights Reserved

Researchers and marketers dont agree on future of nand flash SSD

Marketers particular those involved with anything resembling Solid State Devices (SSD) will tell you SSD is the future as will some researchers along with their fans and pundits. Some will tell you that the future only has room for SSD with the current flavor de jour being nand flash (both Single Level Cell aka SLC and Multi Level Cell aka MLC) with any other form of storage medium (e.g. Hard Disk Drives or HDD and tape summit resources) being dead and to avoid wasting your money on them.

Of course others and their fans or supporters who do not have an SSD play or product will tell forget about them, they are not ready yet.

Then there are those who take no sides per say, simply providing comments and perspectives along with things to be considered that also get used to spin stories for or against by others.

For the record, I have been a fan and user of various forms of SSD along with other variations of tiered storage mediums using them for where they fit best for several decades as a customer in IT, as a vendor, analyst and advisory consultant. Thus my perspective and opinion is that SSDs do in fact have a very bright future. However I also believe that other storage mediums are not dead yet although their roles are evolving while their technologies continue be developed. In other words, use the right technology and tool, packaged and deployed in the best most effective way for the task at hand.

Memory and tiered storage hirearchy
Memory and tiered storage hierarchy

Consequently while some SSD vendors, their fans, supporters, pundits and others might be put off by some recent UCSD research that does not paint SSD and particular nand flash in the best long-term light, it caught my attention and here is why. First I have already seen in different venues where some are using the research as a tool, club or weapon against SSD and in particular nand flash which should be no surprise. Secondly I have also seen those who don’t agree with the research at best dismiss the findings. Others are using it as a conversation or topic piece for their columns or other venues such as here.

The reason the UCSD research caught my eye was that it appeared to be looking at how will nand SSD technology evolve from where it is today to where it will be in ten years or so.

While ten years may seem like a long time, just look back at how fast things evolved over the past decade. Granted the UCSD research is open to discussion, debate and dismissal as clear in the comments of this article here. However the research does give a counter point or perspective to some of the hype which can mean somewhere between the two extremes, exists reality and where things are headed or need to be discussed. While I do not agree with all the observations or opinions of the research, it does give stimulus for discussing things including best practices around deployment vs. simply talking about adoption.

It has taken many decades for people to become comfortable or familiar with the pros and cons of HDD or tape for that matter.

Likewise some are familiar with (good or bad) with DRAM based SSD of earlier generations. On the other hand, while many people use various forms of nand flash SSD ranging from what is inside their cell phone or SD cards for cameras to USB thumb drives to SSD on drives, on PCIe cards or in storage systems and appliances, there is still an evolving comfort and confidence level for business and enterprise storage use. Some have embraced, some have dismissed, many if not most are intrigued wanting to know more, are using nand flash SSD in some shape or form, while gaining confidence.

Part of gaining confidence is moving beyond the industry hype looking at and understanding what are the pros, cons and how to leverage or work around the constraints. A long time ago a wise person told me that it is better to know the good, bad and ugly about a product, service or technology so that you could leverage the best, configure, plan and manage around the bad to avoid or minimized the ugly. Based on that philosophy I find many IT customers and even some VARs and vendors wanting to know the good, the bad and they ugly not for hanging out a vendor or their technology and products, rather so that they can be comfortable in knowing when, where, why and how to use to be most effective.

Industry Trends and Perspectives

Granted to get some of the not so good information may need NDA (Non Disclosure Agreement) or other confidentially discussions as after all, what vendor or solution provider wants to show or let anything less than favorable out into the blogosphere, twittersphere, googleplus, tabloids, news sphere or other competitive landscapes venues.

Ok, lets bring this back to the UCSD research report titled The Bleak Future of NAND Flash Memory

UCSD research report: The Bleak Future of NAND Flash Memory
Click here or on the above image to read the UCSD research report

I’m not concerned that the UCSD research was less than favorable as some others might be, after all, it is looking out into the future and if a concern, provides a glimpse of what to keep an eye on.

Likewise, looking back, the research report could be taken as simply a barometer of what could happen if no improvements or new technologies evolve. For example, the HDD would have hit the proverbial brick wall also known as the super parametric barrier many years ago if new recording methods and materials had not been deployed including a shift to perpendicular recording, something that was recently added to tape.

Tomorrows SSDs and storage mediums will still be based on nand flash including SLC, MLC, eMLC along with other variants not to mention phased change memory (PCM) and other possible contenders.

Todays SSDs have shifted from being DRAM based with HDD or even flash-based persistent backing storage to nand flash-based, both SLC and MLC with enhanced or enterprise MLC appearing. Likewise the density of SSDs continue to increase meaning more data packed into the same die or footprint, more dies stacked in a chip package to boost capacity while decreasing cost. However what is also happening is behind the scenes which is a big differentiator with SSDs and that is the quality of some firmware and low-level page management at the flash translation layer (FTL). Hence they saying that anybody with a soldering iron and ability to pull together off the shelves FTLs and packaging can create some form of an SSD. How effective a product will be is based on the intelligence and robustness of the combination of the dies, FTL, controller and associated firmware and device drivers along with other packaging options plus the testing, validation and verification they undergo.

Various packaging options and where SSD can be deployed
Various SSD locations, types, packaging and usage scenario options

Good SSD vendors and solution providers I believe will be able to discuss your concerns around endurance, duty cycles, data integrity and other related topics to set up confidence with current and future issues, granted you may have to go under NDA to gain that insight. On the other hand, those who feel threatened or not able or interested in addressing or demonstrating confidence for the long haul will be more likely to dismiss studies, research, reports, opinions or discussions that dig deeper into creating confidence via understanding of how things work so that customers can more fully leverage those technologies.

Some will view and use reports such as the one from UCSD as a club or weapon against SSD and in particular against nand flash to help their cause or campaign while others will use it to stimulate controversy and page hit views. My reason for bringing up the topic and discussion it to stimulate thinking and help increase awareness and confidence in technologies such as SSD near and long-term. Regardless of if your view is that SSD will replace HDD, or that they will continue to coexist as tiered storage mediums into the future, gaining confidence in the technologies along with when, where and how to use them are important steps in shifting from industry adoption to customer deployment.

What say you?

Is SSD the best thing and you are dumb or foolish if you do not embrace it totally or a fan, pundit cheerleader view?

Or is SSD great when and where used in the right place so embrace it?

How will SSD continue to evolve including nand and other types of memories?

Are you comfortable with SSD as a long term data storage medium, or for today, its simply a good way to discuss performance bottlenecks?

On the other hand, is SSD interesting, however you are not comfortable or have confidence with the technology, yet you want to learn more, in other words a skeptics view?

Or perhaps the true cynic view which is that SSD are nothing but the latest buzzword bandwagon fad technology?

Ok, nuff said for now, other than here is some extra related SSD material:
SSD options for Virtual (and Physical) Environments: Part I Spinning up to speed on SSD
SSD options for Virtual (and Physical) Environments, Part II: The call to duty, SSD endurance
Part I: EMC VFCache respinning SSD and intelligent caching
Part II: EMC VFCache respinning SSD and intelligent caching
IT and storage economics 101, supply and demand
2012 industry trends perspectives and commentary (predictions)
Speaking of speeding up business with SSD storage
New Seagate Momentus XT Hybrid drive (SSD and HDD)
Are Hard Disk Drives (HDDs) getting too big?
Industry adoption vs. industry deployment, is there a difference?
Data Center I/O Bottlenecks Performance Issues and Impacts
EMC VPLEX: Virtual Storage Redefined or Respun?
EMC interoperability support matrix

Cheers
gs

Greg Schulz – Author Cloud and Virtual Data Storage Networking (CRC Press, 2011), The Green and Virtual Data Center (CRC Press, 2009), and Resilient Storage Networks (Elsevier, 2004)

twitter @storageio

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2012 StorageIO and UnlimitedIO All Rights Reserved

Speaking of speeding up business with SSD storage

Solid state devices (SSD) are a popular topic gaining both industry adoption and customer deployment to speed up storage performance. Here is a link to a recent conversation that I had with John Hillard to discuss industry trends and perspectives pertaining to using SSD to boost performance and productivity for SMB and other environments.

I/O consolidation from Cloud and Virtual Data Storage Networking (CRC Press) www.storageio.com/book3.html

SSDs can be a great way for organizations to do IO consolidation to reduce costs in place of using many hard disk drives (HDDs) grouped together to achieve a certain level of performance. By consolidating the IOs off of many HDDs that often end up being under utilized from a space capacity basis, organizations can boost performance for applications while reducing, or reusing HDD based storage capacity for other purposes including growth.

Here is some related material and comments:
Has SSD put Hard Disk Drives (HDDs) On Endangered Species List?
SSD and Storage System Performance
Are Hard Disk Drives (HDDs) getting too big?
Solid state devices and the hosting industry
Achieving Energy Efficiency using FLASH SSD
Using SSD flash drives to boost performance

Four ways to use SSD storage
4 trends that shape how agencies handle storage
Giving storage its due

You can read a transcript of the conversation and listen to the pod cast here, or download the MP3 audio here.

Ok, nuff said about SSD (for now)

Cheers Gs

Greg Schulz – Author Cloud and Virtual Data Storage Networking (CRC Press, 2011), The Green and Virtual Data Center (CRC Press, 2009), and Resilient Storage Networks (Elsevier, 2004)

twitter @storageio

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2011 StorageIO and UnlimitedIO All Rights Reserved

The Many Faces of Solid State Devices/Disks (SSD)

Storage I/O trends

Here’s a link to a recent article I wrote for Enterprise Storage Forum titled “Not a Flash in the PAN” providing a synopsis of the many faces, implementations and forms of SSD based technologies that includes several links to other related content.

A popular topic over the past year or so has been SSD with FLASH based storage for laptops, also sometimes referred to as hybrid disk drives along with announcements late last year by companies such as Texas Memory Systems (TMS) of a FLASH based storage system combining DRAM for high speed cache in their RAMSAN-500 and more recently EMC adding support for FLASH based SSD devices in their DMX4 systems as a tier-0 to co-exist with other tier-1 (fast FC) and tier-2 (SATA) drives.

Solid State Disks/Devices (SSD) or memory based storage mediums have been around for decades, they continue to evolve using different types of memory ranging from volatile dynamic random access (DRAM) memory to persistent or non-volatile RAM (NVRAM) and various derivatives of NAND FLASH among other users. Likewise, the capacity cost points, performance, reliability, packaging, interfaces and power consumption all continue to improve.

SSD in general, is a technology that has been miss-understood over the decades particularly when simply compared on a cost per capacity (e.g. dollar per GByte) basis which is an unfair comparison. The more approaches comparison is to look at how much work or amount of activity for example transactions per second, NFS operations per second, IOPS or email messages that can be processed in a given amount of time and then comparing the amount of power and number of devices to achieve a desired level of performance. Granted SSD and in particular DRAM based systems cost more on a GByte or TByte basis than magnetic hard disk drives however it also requires more HDDs and controllers to achieve the same level of performance not to mention requiring more power and cooling than compared to a typical SSD based device.

The many faces of SSD range from low cost consumer grade products based on consumer FLASH products to high performance DRAM based caches and devices for enterprise storage applications. Over the past year or so, SSD have re-emerged for those who are familiar with the technology, and emerged or appeared for those new to the various implementations and technologies leading to another up swinging in the historic up and down cycles of SSD adoption and technology evolution in the industry.

This time around, a few things are different and I believe that SSD in general, that is, the many difference faces of SSD will have staying power and not fade away into the shadows only to re-emerge a few years later as has been the case in the past.

The reason I have this opinion is based on two basic premises which are economics and ecological”. Given the focus on reducing or containing costs, doing more with what you have and environmental or ecological awareness in the race to green the data center and green storage, improving on the economics with more energy efficiency storage, that is, enabling your storage to do more work with less energy as opposed to avoiding energy consumption, has the by product of improved economics (cost savings and improved resource utilization and better service delivery) along with ecological (better use of energy or less use of energy).

Current implementations of SSD based solutions are addressing both the energy efficiency topics to enable better energy efficiency ranging from maximizing battery life to boosting performance while drawing less power. Consequently we are now seeing SSD in general are not only being used for boosting performance, also we are seeing it as one of many different tools to address power, cooling, floor space and environmental or green storage issues.

Here’s a link to a StorageIO industry trends and perspectives white paper at www.storageio.com/xreports.htm.

Here’s the bottom line, there are many faces to SSD. SSD (FLASH or DRAM) based solutions and devices have a place in a tiered storage environment as a Tier-0 or as an alternative in some laptop or other servers where appropriate. SSD compliments other technologies and SSD benefits from being paired with other technologies including high performance storage for tier-1 and near-line or tier-2 storage implementing intelligent power management (IPM).

Cheers gs

Greg Schulz – Author Cloud and Virtual Data Storage Networking (CRC Press, 2011), The Green and Virtual Data Center (CRC Press, 2009), and Resilient Storage Networks (Elsevier, 2004)

twitter @storageio

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2012 StorageIO and UnlimitedIO All Rights Reserved