Category: ssd

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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

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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.

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2024 Server StorageIO and UnlimitedIO. All Rights Reserved. StorageIO is a registered Trade Mark (TM) of Server StorageIO.

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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

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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