How much SSD do you need vs. want?

Storage I/O Industry Trends and Perspectives

I have been getting asked by IT customers, VAR’s and even vendors how much solid state device (SSD) storage is needed or should be installed to address IO performance needs to which my standard answer is it depends.

I also am also being asked if there is rule of thumb (RUT) of how much SSD you should have either in terms of the number of devices or a percentage; IMHO, the answer is it depends. Sure, there are different RUTs floating around based on different environments, applications, workloads however are they applicable to your needs.

What I would recommend is instead of focusing on percentages, RUTs, or other SWAG estimate’s or PIROMA calculations, look at your current environment and decide where the activity or issues are. If you know how many fast hard disk drives (HDD) are needed to get to a certain performance level and amount of used capacity that is a good starting point.

If you do not have that information, use tools from your server, storage or third-party provider to gain insight into your activity to help size SSD. Also if you have a database environment and are not familiar with the tools, talk with your DBA’s to have them run some reports that show performance information the two of you can discuss to zero in hot spots or opportunity for SSD.

Keep in mind when looking at SSD what is that you are trying to address by installing SSD. For example, is there a specific or known performance bottleneck resulting in poor response time or latency or is there a general problem or perceived opportunity?

Storage I/O Industry Trends and Perspectives

Is there a lack of bandwidth for large data transfers or is there a constraint on how many IO operations per second (e.g. IOPS) or transaction or activity that can be done in a given amount of time. In other words the more you know where or what the bottleneck is including if you can trace it back to a single file, object, database, database table or other item the closer you are to answering how much SSD you will need.

As an example if using third-party tools or those provided by SSD vendors or via other sources you decide that your IO bottleneck are database transaction logs and system paging files, then having enough SSD space capacity to fit those in part of the solution. However, what happens when you remove the first set of bottlenecks, what new ones will appear and will you have enough space capacity on your SSD to accommodate the next in line hot spot?

Keep in mind that you may want more SSD however what can you get budget approval to buy now without having more proof and a business case. Get some extra SSD space capacity to use for what you are confident can address other bottlenecks, or, enable new capabilities.

On other hand if you can only afford enough SSD to get started, make sure you also protect it. If you decide that two SSD devices (PCIe cache or target cards, drives or appliances) will take care of your performance and capacity needs, make sure to keep availability in mind. This means having extra SSD devices for RAID 1 mirroring, replication or other form of data protection and availability. Keep in mind that while traditional hard disk drive (HDD) storage is often gauged on cost per capacity, or dollar per GByte or dollar per TByte, with SSD measure its value on cost to performance. For example, how many IOPS, or response time improvement or bandwidth are obtained to meet your specific needs per dollar spent.

Related links
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
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)
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

Is SSD dead? No, however some vendors might be

Storage I/O trends

Is SSD dead? No, however some vendors might be

In a recent conversation with Dave Raffo about the nand flash solid state disk (SSD) market, we talked about industry trends, perspectives and where the market is now as well as headed. One of my comments is, has been and will remain that the industry has still not reached anywhere near full potential for deployment of SSD for enterprise, SMB and other data storage needs. Granted, there is broad adoption in terms of discussion or conversation and plenty of early adopters.

SSD and in particular nand flash is anything but dead, in fact in the big broad picture of things, it is still very early in the game. Sure, for those who cover and crave the newest, latest and greatest technology to talk about, nand flash SSD might seem old, yesterday news, long in the tooth and time for something else. However, for those who are focused on deployment vs. adoption such as customers, in general, nand flash SSD in its many packaging options has still not yet reached its full potential.

Despite the hype, fanfare from CEOs or their evangelist along with loyal followers of startups that help drive industry adoption (e.g. what is talked about), there is still lots of upside growth in the customer drive industry deployment (actually buying, installing and using) for nand flash SSD.

What about broad customer deployments?

Sure, there are the marquee customer success stories that you need a high-capacity SAS or SATA drive to hold the YouTube videos, slide decks, press releases for.

However, have we truly, reached broad customer deployment or broad industry adoption?

Hence, I see more startups coming into the market space, and some exiting on their own, via mergers and acquisition or other means.

Will we see a feeding frenzy or IPO craze as with earlier hype cycles of technologies, IMHO there will be some companies that get the big deal, some will survive as new players running as a business vs. running to be acquired or IPO. Others will survive by evolving into something else while others will join the where are they now list.

If you are a SSD startup, CEO, CxO, or marketer, their PR, evangelist or loyal follower do not worry as the SSD market and even nand flash is far from being dead. On the other hand, if you think that it has hit its full stride, you are missing either the bigger picture, or too busy patting yourselves on the back for a job well done. There is much more opportunity out there and not even all the low hanging fruit has been picked yet.

Check out the conversation with Dave Raffo along with comments from others here.

Related links on storage IO metrics and SSD performance
What is the best kind of IO? The one you do not have to do
Is SSD dead? No, however some vendors might be
Storage and IO metrics that matter
IO IO it is off to Storage and IO metrics we go
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)
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)
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 and IO metrics that matter

It is great to see more conversations and coverage around storage metrics that matter beyond simply focusing on cost per GByte or TByte (e.g. space capacity). Likewise, it is also good to see conversations expanding beyond data footprint reduction (DFR) from a space capacity savings or reduction ratio to also address data movement and transfer rates. Also good to see is increase in discussion around input/output operations per section (IOPs) tying into conversations from virtualization, VDI, cloud to Sold State Devices (SSD).

Other storage and IO metrics that matter include latency or response time, which is how fast work is done, or time spent. Latency also ties to IOPS in that as more work arrives to be done (IOPS) of various size, random or sequential, reads or writes, queue depths are an indicator of how well work is flowing. Another storage and IO metric that matters is availability because without it, performance or capacity can be affected. Likewise, without performance, availability can be affected.

Needless to say that I am just scratching the surface here with storage and IO metrics that matter for physical, virtual and cloud environments from servers to networks to storage.

Here is a link to a post I did called IO, IO, it is off to storage and IO metrics we go that ties in themes of performance measurements and solid-state disk (SSD) among others. Also check out this piece about why VASA (VMware storage analysis metrics) is important to have your VMware CASA along with Windows boot storage and IO performance for VDI and traditional planning purposes.

Check out this post about metrics and measurements that matter along with this conversation about IOPs, capacity, bandwidth and purchasing discussion topics.

Related links on storage IO metrics and SSD performance
What is the best kind of IO? The one you do not have to do
Is SSD dead? No, however some vendors might be
Storage and IO metrics that matter
IO IO it is off to Storage and IO metrics we go
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)
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)
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

What is the best kind of IO? The one you do not have to do

What is the best kind of IO? The one you do not have to do

data infrastructure server storage I/O trends

Updated 2/10/2018

What is the best kind of IO? If no IO (input/output) operation is the best IO, than the second best IO is the one that can be done as close to the application and processor with best locality of reference. Then the third best IO is the one that can be done in less time, or at least cost or impact to the requesting application which means moving further down the memory and storage stack (figure 1).

Storage and IO or I/O locality of reference and storage hirearchy
Figure 1 memory and storage hierarchy

The problem with IO is that they are basic operation to get data into and out of a computer or processor so they are required; however, they also have an impact on performance, response or wait time (latency). IO require CPU or processor time and memory to set up and then process the results as well as IO and networking resources to move data to their destination or retrieve from where stored. While IOs cannot be eliminated, their impact can be greatly improved or optimized by doing fewer of them via caching, grouped reads or writes (pre-fetch, write behind) among other techniques and technologies.

Think of it this way, instead of going on multiple errands, sometimes you can group multiple destinations together making for a shorter, more efficient trip; however, that optimization may also take longer. Hence sometimes it makes sense to go on a couple of quick, short low latency trips vs. one single larger one that takes half a day however accomplishes many things. Of course, how far you have to go on those trips (e.g. locality) makes a difference of how many you can do in a given amount of time.

What is locality of reference?

Locality of reference refers to how close (e.g location) data exists for where it is needed (being referenced) for use. For example, the best locality of reference in a computer would be registers in the processor core, then level 1 (L1), level 2 (L2) or level 3 (L3) onboard cache, followed by dynamic random access memory (DRAM). Then would come memory also known as storage on PCIe cards such as nand flash solid state device (SSD) or accessible via an adapter on a direct attached storage (DAS), SAN or NAS device. In the case of a PCIe nand flash SSD card, even though physically the nand flash SSD is closer to the processor, there is still the overhead of traversing the PCIe bus and associated drivers. To help offset that impact, PCIe cards use DRAM as cache or buffers for data along with Meta or control information to further optimize and improve locality of reference. In other words, help with cache hits, cache use and cache effectiveness vs. simply boosting cache utilization.

Where To Learn More

View additional NAS, NVMe, SSD, NVM, SCM, Data Infrastructure and HDD related topics via the following links.

Additional learning experiences along with common questions (and answers), as well as tips can be found in Software Defined Data Infrastructure Essentials book.

Software Defined Data Infrastructure Essentials Book SDDC

What This All Means

What can you do the cut the impact of IO

  • Establish baseline performance and availability metrics for comparison
  • Realize that IOs are a fact of IT virtual, physical and cloud life
  • Understand what is a bad IO along with its impact
  • Identify why an IO is bad, expensive or causing an impact
  • Find and fix the problem, either with software, application or database changes
  • Throw more software caching tools, hyper visors or hardware at the problem
  • Hardware includes faster processors with more DRAM and fast internal busses
  • Leveraging local PCIe flash SSD cards for caching or as targets
  • Utilize storage systems or appliances that have intelligent caching and storage optimization capabilities (performance, availability, capacity).
  • Compare changes and improvements to baseline, quantify improvement

Ok, nuff said, for now.

Gs

Greg Schulz – Microsoft MVP Cloud and Data Center Management, VMware vExpert 2010-2017 (vSAN and vCloud). Author of Software Defined Data Infrastructure Essentials (CRC Press), as well as Cloud and Virtual Data Storage Networking (CRC Press), The Green and Virtual Data Center (CRC Press), Resilient Storage Networks (Elsevier) and twitter @storageio. Courteous comments are welcome for consideration. First published on https://storageioblog.com any reproduction in whole, in part, with changes to content, without source attribution under title or without permission is forbidden.

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