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.

Best Practices for CSV defrag in Hyper-V (Windows Server 2008R2)

by Michael 28. March 2011 04:33

One of the most significant features in Windows 2008R2 (for Hyper-V) is Cluster Shared Volumes (CSV) for virtual disks (vhd). This allows NTFS to behave similar to a clustered file system, addressing many limitations found in Hyper-V storage with the original release (Windows 2008).  

There are three online modes/states for CSV:
  • Direct Access: In this state, the CSV is available to all nodes in the cluster (i.e. all your VMs) for direct high performance storage access. This is the state you want in production.  
  • Redirected Access: In this state, the CSV is still available to all nodes in the cluster, but all I/O is redirected through a single "coordinator" node. Redirected access is used in planned situations where you need to perform certain disk actions that can't have multiple nodes accessing and locking files concurrently, such as a VSS backup or defrag. Channeling all I/O through a coordinator slows I/O and is more likely to cause bottlenecks for production demands.
  • Maintenance mode: enabling this mode is a safe means to get to a state where processes that require exclusive access to a volume can be used, such as a maintenance routine like chkdsk.

Best Practice: 

  • On the Hyper-V system volume,  pass-through volumes and any other non-CSV volumes, leave Automatic Defragmentation on at all times.
  • Given the performance benefits of Direct Access for cluster shared volumes, leave IntelliWrite on and run an occasional scheduled defrag. This is because of the requirement to use the coordinator node and place the volume into a Redirect Access state. Automatically changing from direct to redirect and back is all part of the file system control (kernel code we co-wrote with MS in the mid 90’s – as a Windows source code licensee), and the mechanism all defragmenters use today - you do not need to do anything special.
  • Correction (June 30, 2011): In the process of testing for the V-locity 3.0 release, we discovered that defagmentation does NOT cause a state change to Redirected Access. This is true for any defragmenter. So, defragment CSVs as you would any other volume. [Apologies on making this statement without validation - we should know better :-)] 

Diskeeper and V-locity are fully compatible with CSVs as confirmed by Windows IT Pro here. The file system control built into Windows is used to defrag, but not used for prevention in the design of IntelliWrite, which is a CSV-compatible file system filter driver (it's very important for drivers to be CSV-compatible) residing at a low altitude, expect on XP (where its altitude is much higher). You can view all file system minifilters and their allocated altitudes here.

IntelliWrite is “DKRtWrt” (its code names in development stages was WriteRight and then later RightWrite -hence "RtWrt"). To see or load/unload filter drivers, use the Filter Manager Control Program (fltmc):

Tags: , , , ,

Defrag | Hyper-V | IntelliWrite | V-Locity

All Around the World (part deux)

by Colleen Toumayan 18. February 2011 07:07

 

“I am the person who proposed Diskeeper a few years ago in our company because we had some people who were complaining about slow machines. Most of the times the problem was related to the hard disks that were non-stop reading/writing. I tried a few times the internal defragmenter; it helped in reducing the slowness of the machine but it was always for a short time. So I looked for a better product and found Diskeeper.  

I made contact with Diskeeper UK and we had the pleasure to deal with an employee who arranged for an evaluation version of Diskeeper and Diskeeper Administrator to test in our company. 

We have a high number of computers, 16000, which are now running smoothly. The IntelliWrite does a good job preventing fragmentation. The number of calls for slow machines have dropped but we never had real measurements about the performance of Diskeeper. I am very curious about Diskeeper 2011 and what it can bring more so than this version. Diskeeper works and it is a good product. The price is also very good." 

Marc Vanderhaegen, SNCB (Société nationale des Chemins de fer belges)

Desktop Management

Brussels, Belgium

Tags:

IntelliWrite | Success Stories

Defragmenting IT Healthcare

by Michael 20. December 2010 05:18

Joe Marion is founder and Principal of Healthcare Integration Strategies, specializing in the integration of imaging technologies with the overall healthcare IT landscape. His blog (at Healthcare Informatics) covers challenges and opportunities specifically relevant to optimizing Healthcare IT initiatives.

Medical images are a significant percentage of the the world's storage requirements, and have been predicted to encompass an even greater percentage of future storage demand. In Joe's recent blog post he posed the question "Is Defragmentation a Boon to Healthcare IT Performance?"

In his post he includes personal observations and insight into performance implications fragmentation can incur on IT as healthcare departments themselves consolidate and standardize application use:

"With departmental solutions, there very likely was less emphasis on system tools such as defragmentation applications.  Now that PACS technology is becoming more intertwined with the rest of IT, there should be greater emphasis on inclusion of these tools.  In addition, server virtualization can mean that previously independent applications are now part of a virtual server farm."

He also makes the astute observation that centralizing computing and storage magnifies bottlenecks, making a solution such as defragmentation increasingly more vital:

"The addition of disk-intensive applications such as speech recognition and imaging could potentially impact the overall performance of these applications.  As data storage requirements within healthcare grow, the problem will potentially get worse.  Think of the consequence of managing multiple 3000-slice CT studies and performing multiple 3D analyses.  As more advanced visualization applications go the client-server route, the performance of a central server doing the 3D processing could be significantly impacted."

You can read Joe's blog here.

  

Tags: , , ,

Defrag | Diskeeper | IntelliWrite | V-Locity

Diskeeper Wins Gold: Video Review of DIskeeper 2010 from Top Ten Reviews

by Colleen Toumayan 26. October 2010 06:26

Diskeeper 2010 was reviewed on Top Ten Reviews and won the Gold award.

Diskeeper offers a large list of powerful features for both general computer users and advanced experts. Diskeeper is a top performer, surpassing all the other disk defragmenter software reviewed as a result of its impressive feature set and very fast performance.

The video is also here.

Tags: , ,

awards | Defrag | Diskeeper | HyperBoot | IntelliWrite

Defrag on HP EVA SANs - 45 million fragments handled

by Colleen Toumayan 12. May 2010 11:49

We have been running Diskeeper 2010 EnterpriseServer for two months on an HP EVA SAN 4000 and 4400, with 4 1TB volumes each.  

Diskeeper removed over 45 million fragments in the last two months on a specific volume that had only 15% free space, and IntelliWrite prevented 24,000 fragments. I believe that will be even better as soon as we can extend this volume to two TB. 

We see a big improvement on the backup time which came down from 48 hours to 32 now, and it’s still going down. 

I believe Diskeeper worth the price and I never had any trouble with software from Diskeeper Corporation, so that alone narrowed the field of choices. 

Jean-François Poirier
Technicien Telecommunication
Spectra Premium Industries Inc.

Tags:

Diskeeper | IntelliWrite | SAN | Success Stories

Month List

Calendar

<<  November 2017  >>
MoTuWeThFrSaSu
303112345
6789101112
13141516171819
20212223242526
27282930123
45678910

View posts in large calendar