Condusiv Technologies Blog

Condusiv Technologies Blog

Blogging @Condusiv

The Condusiv blog shares insight into the issues surrounding system and application performance—and how I/O optimization software is breaking new ground in solving those issues.

Causes and Solutions for Latency

by Kim Amezcua 19. December 2019 04:14

Sometimes the slowdown of a Windows server occurs because the device or its operating system is outdated. Other times, the slowdown is due to physical constraints on the retrieval, processing, or transmitting of data. There are other causes as we will cover. In any case, the delay between when a command is made and a response is received is referred to as "latency."

Latency is a measure of time. For example, the latency of a command might be 0.02 seconds. To humans, this seems extraordinarily fast. However, computer processors can execute billions of instructions per second. This means that latency of a few millionths of a second can cause visible delays in the operation of a computer or server.

To figure out how to improve latency, you must identify the source of any latency issues. There are many possible sources of latency and, for each one, there are high latency fixes. Here are two possible causes of latency as well as a brief explanation for how to improve latency. In this case, I/O latency where the computer process is waiting for the I/O to complete, so it can process the data of that I/O, is a   waste of your computer processing power.

Data Fragments

Logical data fragments occur when files are written, deleted, and rewritten to a hard drive or solid-state drive.

When files are deleted from a drive, the files actually still exist on the drive. However, the logical address on the Windows operating file system for those files is freed up for use. This means that "deleted" files remain on the logical drive until another file is written over it by reusing the address. (This also explains why it is possible to recover lost files). 

When an address is re-used, the likelihood that the new file is exactly the same length as the "deleted" file is remote. As a result, little chunks or fragments of data remaining from the "deleted" file remain on the logical drive. As a logical drive fills up, new files are sometimes broken up to fit into the available segments. At its worst, a logical fragmented drive contains both old fragments left over from deleted files (free space fragments) and new fragments that were intentionally created (data file fragments).

Logical data fragments can be a significant source of latency in a computer or server. Storing to, and retrieving from, a fragmented logical drive introduces additional steps in searching for and reassembling files around the fragments. For example, rather than reading a file in one or two I/Os, fragmentation can require hundreds, even thousands of I/Os to read or write that same data.

One way for how to improve latency from these logical data fragments is to defragment the logical drive by collecting data fragments and making them contiguous. The main disadvantages of defragmenting are that it must be repeated periodically because the logical drive will inevitably fragment again and also defragmenting SSDs can cause them to wear out prematurely.

A better method for how to improve latency from disk fragments is to prevent the logical disk from becoming fragmented. Diskeeper® 18 manages writes so that large, contiguous segments are kept together from the very start, thereby preventing the fragments from developing in the first place.

Limited Resources

No matter how "fast" the components of a computer are, they are still finite and tasks must be scheduled and performed in order. Certain tasks must be put off while more urgent tasks are executed. Although the latency in scheduling is often so short that it is unnoticeable, there will be times when limited resources cause enough of a delay that it hampers the computer or server.

For example, two specifications that are commonly used to define the speed of a computer are processor clock speed and instructions per cycle. Although these numbers climb steadily as technology advances, there will always be situations where the processor has too many tasks to execute and must delay some of them to get them all done.

Similarly, data buses and RAM have a particular speed. This speed limits the frequency with which data can be moved to the processor. These kinds of Input/output performance delays can reduce a system’s capacity by more than 50%.

One way to address latency is a method used by Diskeeper® 18. In this method, idle available DRAM is used to cache hot reads. By caching, it eliminates having to travel all the way to the storage infrastructure to read the data; and remember that DRAM can be 10x-15x faster than SSDs and even many factors more than HDDs. This allows faster retrieval of data; in fact, Windows systems can run faster than when new.

Reducing latency is mostly a matter of identifying the source of latencies and addressing them. By being proactive and preventing fragmentation before it happens and by caching hot reads using idle & available DRAM, Diskeeper® 18 makes Windows computers faster and more reliable.

 

What Condusiv’s Diskeeper Does for Me

by Tim Warner, Microsoft Cloud & Datacenter MVP 4. November 2019 05:36

I'm a person who uses what he has. For example, my friend Roger purchased a fancy new keyboard, but only uses it on "special occasions" because he wants to keep the hardware in pristine condition. That isn't me--my stuff wears out because I rely on it and use it continuously.

To this point, the storage on my Windows 10 workstation computer takes a heavy beating because I read and write data to my hard drives every single day. I have quite an assortment of fixed drives on this machine:

·         mechanical hard disk drive (HDD)

·         "no moving parts" solid state drive (SSD)

·         hybrid SSD/HDD drive

Today I'd like to share with you some ways that Condusiv’s Diskeeper helps me stay productive. Trust me--I'm no salesperson. Condusiv isn't paying me to write this article. My goal is to share my experience with you so you have something to think about in terms of disk optimization options for your server and workstation storage.

Diskeeper® or SSDKeeper®?

I've used Diskeeper on my servers and workstations since 2000. How time flies! A few years ago it confused me when Condusiv released SSDkeeper, their SSD optimization tool that works by optimizing your data as its written to disk.

Specifically, my confusion lay in the fact you can't have Diskeeper and SSDkeeper installed on the same machine simultaneously. As you saw, I almost always have a mixture of HDD and SSD drives. What am I losing by installing either Diskeeper or SSDkeeper, but not both?

You lose nothing because Diskeeper and SSDkeeper share most of the same features. Diskeeper like SSDkeeper can optimize solid-state disks using IntelliMemory Caching and IntelliWrite, and SSDkeeper like Diskeeper can optimize magnetic disks using Instant Defrag. Both products can automatically determine the storage type and apply the optimal technology.

Thus, your decision of whether to purchase Diskeeper or SSDkeeper is based on which technology the majority of your disks use, either HDD or SSD.

Allow me to explain what those three product features mean in practice:

·         IntelliMemory®: Uses unallocated system random access memory (RAM) for disk read caching

·         IntelliWrite®: Prevents fragmentation in the first place by writing data sequentially to your hard drive as its

created

·         Instant Defrag™: Uses a Windows service to perform "just in time" disk defragmentation

In Diskeeper, click Settings > System > Basic to verify you're taking advantage of these features. I show you the interface in Figure 1.

 

Figure 1. Diskeeper settings.

What about external drives?

In Condusiv's Top FAQs document you'll note that Diskeeper no longer supports external drives. Their justification for this decision is that their customers generally do not use external USB drives for high performance, input/output (I/O) intensive applications.

If you want to run optimization on external drives, you can do that graphically with the Optimize Drives Windows 10 utility, or you can run defrag.exe from an elevated command prompt.

For example, here I am running a fragmentation analysis on my H: volume, an external SATA HDD:

PS C:\users\tim> defrag H: /A

Microsoft Drive Optimizer

Copyright (c) Microsoft Corp.

Invoking analysis on TWARNER1 (H:)...

The operation completed successfully.

Post Defragmentation Report:

         Volume Information:

                Volume size                 = 1.81 TB

                Free space                  = 1.44 TB

                Total fragmented space      = 0%

                Largest free space size     = 1.43 TB

         Note: File fragments larger than 64MB are not included in the fragmentation statistics.

         You do not need to defragment this volume.

PS C:\users\tim>              

Let's look at the numbers!

All Condusiv products make it simple to perform benchmark analyses and run progress reports, and Diskeeper is no exception to this rule. Look at Figure 2--since I rebuilt my Windows 10 workstation and installed Diskeeper in July 2018, I've saved over 20 days of storage I/O time!

Figure 2. Diskeeper dashboard.

Those impressive I/O numbers don't strain credulity when you remember that Diskeeper aggregates I/O values across all my fixed drives, not only one. This time saving is the chief benefit Diskeeper gives me as a working IT professional. The tool gives me back seconds that otherwise I'd spend waiting on disk operations to complete; I then can use that time for productive work instead.

Even more to the point, Diskeeper does this work for me in the background, without my having to remember to run or even schedule defragmentation and optimization jobs. I'm a huge fan of Diskeeper, and I hope you will be.

Recommendation

Condusiv offers a free 30-day trial that you can download and see how much time it can save you:

Diskeeper 30-day trial

SSDkeeper 30-day trial

Note: If you have a virtual environment, you can download a 30-day trial of Condusiv’s V-locity (you can also see my review of V-locity 7).

 

Timothy Warner is a Microsoft Most Valuable Professional (MVP) in Cloud and Datacenter Management who is based in Nashville, TN. His professional specialties include Microsoft Azure, cross-platform PowerShell, and all things Windows Server-related. You can reach Tim via Twitter (@TechTrainerTim), LinkedIn or his website, techtrainertim.com.

  

Condusiv’s V-locity Technology Was Recently Certified as Citrix Ready

by Dawn Richcreek 11. September 2019 09:51

 

We are proud to announce that Condusiv’s V-locity® I/O reduction software has been certified as Citrix Ready®. The Citrix Ready program helps customers identify third-party solutions that enhance virtualization, networking and cloud computing solutions from Citrix Systems, Inc. V-locity, our innovative and dynamic alternative to costly hardware overhauls, has completed a rigorous verification process to ensure compatibility with Citrix solutions, providing confidence in joint solution efficiency and value. The Citrix Ready program makes it easy for customers to identify complementary products and results-driven solutions that can enhance Citrix environments and increase productivity.

 

 

 

Verified Performance Improvements of 50 Percent or More

To obtain the Citrix Ready certification, we ran IOMeter benchmark tests—an industry standard tool for testing I/O performance—on a Windows 10 system powered by Citrix’s XenDesktop virtual desktop access (VDA).  

The IOMeter benchmark utility was set up to run 5 different tests with variations in the following parameters:

 •  Different read/write size packets (512b to 64kb)
 •  Different read/write ratios, i.e. 50% read/50% writes, 75% reads/25% writes
 •  Different mixture of random and sequential I/Os

The tests determined that drastic improvements were made with V-locity enabled versus disabled. With V-locity enabled, we found that performance rates improved around 50% on average. In one test case, IOps (I/Os per second) increased from 2,903 to 5,525, a performance rate improvement of 90%.  

 

 

 

 This chart shows the detailed test results of the 5 test variations:  

 

 

 

We also compared the results of the V-locity Dashboard running the same IOMeter benchmark, with V-locity disabled and then enabled and found some additional improvements.

With V-locity enabled, it was able to eliminate over 8 million I/Os from having to go through the network and storage to get satisfied which immensely increased the I/O capacity of the system.  By knowing the latency times of these ‘eliminated’ I/Os, another improvement to highlight is that it saved more than an hour of storage I/O time.   

 

 

 

Additionally, the workload (amount of data read/written) increased from 169GB to 273GB, meaning 60% more work was being done in the same amount of time.  

 

 

 

 

 

Customers can be confident that V-locity has successfully passed an exhaustive series of tests established by Citrix. The V-locity technology works effectively with Citrix solutions and can provide customers with 50% or more faster performance gain on their heaviest workloads. V-locity allows customers to “set it and forget it,” meaning that once it is installed, systems will instantly improve with little to no maintenance.

Our CEO, Jim D’Arezzo noted, “We are proud to partner with Citrix Systems. It’s important to remember that most I/O performance issues are caused by the operating system, particularly in the Windows environment. When compared to a hardware upgrade, the software solutions Condusiv offers are far more effective—both in terms of cost and result—in increasing overall system performance. We offer customers intelligent solutions that now combine our V-locity with Citrix XenDesk. We can’t wait to continue to work with the trusted partners in the Citrix Ready ecosystem.” 

 

Download free 30-day trial of V-locity

 

Condusiv’s V-locity I/O reduction software has been certified as Citrix Ready

 

 

Improve Performance Without Getting Stuck with Unnecessary and Expensive Hardware

by Marissa Newman 14. August 2019 04:15

We recently completed a case study with a top construction company who deployed V-locity® I/O reduction software to improve speed on Citrix and SQL applications and avoided unnecessary hardware costs.

Performance on Teichert’s Citrix and SQL servers that were running critical applications was beginning to suffer due to the growth of data, increased number of users, and infrastructure virtualization. When user complaints about the slowness of the live-order entry system, queries taking too long, and poor system performance in general were at a high, Steve Lomax, Teichert’s Senior Windows Systems Administrator, began to look at various solutions to optimize their infrastructure.

Having already been a Diskeeper customer, the company decided to evaluate Condusiv’s V-locity® I/O reduction software and were pleased to find that they no longer needed to implement any of the other solutions they were looking at to optimize performance. Steve explained, “We were surprised to learn that Condusiv had advanced their software to such a degree that they were now proactively optimizing writes in-line, cutting out a ton of write I/O that was previously hammering our SAN. We upgraded from a NetApp tiered storage solution…to a hybrid-flash Tintri T850 and experienced the same results from V-locity regardless of the brand or type of storage we had underlying our data center.”

The company saw major improvement across the board and particularly on their Citrix and SQL servers. On their 30 busiest servers, V-locity had prevented 41% of write I/O traffic from occurring and 50% of read I/O traffic from storage due to DRAM read caching.

Deploying V-locity to their virtual infrastructure eliminated the need to spend money on additional hardware and other 3rd party performance solutions. Steve said, “We were looking at other solutions that could give us a performance boost…[but] were able to skip all that because V-locity solved it with a simple install right into the VM and that’s it. You’re done. I would recommend V-locity to anyone that doesn’t want to be stuck with unnecessary hardware costs and needs a solution to add an extra layer of enhanced performance.”

Steve concluded by describing the positive impacts brought on by V-locity’s performance gains. “We’ve seen at least a 50-60% drop in performance-related issues…General frustration is gone, users are more productive and efficient, customers don’t have to wait long periods of time to process orders, and the IT department is freed up to focus on more important initiatives relating to the company’s mission and core values.”

 

Read the full case study

 

Try V-locity FREE for yourself – no reboot is needed

Overcoming the I/O Blender Effect with V-locity

by Rick Cadruvi, Chief Architect 5. August 2019 05:23

You’ve decided that you want to try out V-locity® software – kick the tires so to speak.  You’ll just load it on one of your Virtual Machines and see how it goes.  What kind of benefit will you see?

It is true that V-locity will likely provide significant benefit on that one VM.  It may even be extraordinary.  But loading V-locity on just one VM on a host with sometimes dozens of VMs won’t give you the biggest bang for your buck. V-locity includes many technologies that address storage performance issues in an extremely intelligent manner.  Part of the underlying design is to learn about the specific loads your system has and intelligently adapt to each specific environment presented to it.   That’s why we created a product especially for Virtual environments in the first place. 

The beauty of V-locity is its ability to deal with something called the I/O Blender Effect.  This is the dark side of virtualized systems.  When there are multiple VMs on a host, or multiple hosts with VMs that use the same back-end storage system (e.g., a SAN) a “blender” effect occurs when all these VMs are sending I/O requests up and down the stack.  As you can guess, it can create huge performance bottlenecks. In fact, perhaps the most significant issue that virtualized environments face is the fact that there are MANY performance chokepoints in the ecosystem, especially the storage subsystem.  These chokepoints are robbing 30-50% of your throughput.  That’s what V-locity can recover.

Look at it this way.  VM “A” may have different resource requirements than VM “B” and so on.  Besides performing different tasks with different workloads, they may have different peak usage periods.  What happens when those peaks overlap?  Worse yet, what happens if several of your VMs have very similar resource requirements and workloads that constantly overlap? 

 

The answer is that the I/O Blender Effect takes over and now VM “A” is competing directly with VM “B” and VM “C” and so on.  The blender pours all those resource desires into a funnel, creating bottlenecks with unpredictable performance results.  What is predictable is that performance will suffer, and likely a LOT.

Enter V-locity.  V-locity was designed from the ground up to intelligently deal with these core issues.  The guiding question in front of us as it was being designed and engineered, was:

Given your workload and resources, how can V-locity help you overcome the I/O Blender Effect?

By making sure that V-locity will adapt to your specific workload and having studied what kinds of I/Os amplify the I/O Blender Effect, we were able to add intelligence to specifically go after those I/Os.  We take a global view.  We aren’t limited to a specific application or workload.  While we do have technologies that shine under certain workloads, such as transactional SQL applications, our goal is to optimize the entire ecosystem.  That’s the only way to overcome the I/O Blender Effect.

So, while we can indeed give you great gains on a single VM, V-locity truly gets to shine and show off its purpose when it can intelligently deal with the chokepoints that create the I/O Blender Effect.  That means you should add V-locity to ALL your VMs.  With our no-reboot installation and a V-locity Management Console, it’s fast and easy to cover and manage your environment.

And yes, this same I/O Blender effect can occur in your physical environment with multiple physical systems all accessing different LUNs on the same SAN. Our Diskeeper® software is the answer here.

Go ahead and try V-locity on the VMs that are in the most competition for resources and you’ll be amazed at the benefits.  The chokepoints aren’t obvious or right in front of your face, but they are real and V-locity is the answer.  After that, just add V-locity to all your VMs, then sit back and see how smart you were to so easily improve throughput across your eco-system.

Video: Condusiv I/O Reduction Software Overview

Download a 30-day Free Trial

 

RecentComments

Comment RSS

Month List

Calendar

<<  January 2020  >>
MoTuWeThFrSaSu
303112345
6789101112
13141516171819
20212223242526
272829303112
3456789

View posts in large calendar