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.

How to Achieve 2X Faster MS-SQL Applications

by Brian Morin 8. November 2017 05:31

By following the best practices outlined here, we can virtually guarantee a 2X or faster boost in your MS-SQL performance with our I/O reduction software.

  1) Don’t just run our I/O reduction software on the SQL Server instances but also on the application servers that run on top of MS-SQL

- It’s not just SQL performance that needs improvement, but the associated application servers that communicate with SQL. Our software will eliminate a minimum of 30-40% of the I/O traffic from those systems.

  2) Run our I/O reduction software on all the non-SQL systems on the same host/hypervisor

- Sometimes a customer is only concerned with improving their SQL performance, so they only install our I/O reduction software on the SQL Server instances. Keep in mind, the other VMs on the same host/hypervisor are interfering with the performance of your SQL instances due to chatty I/O that is contending for the same storage resources. Our software eliminates a minimum of 30-40% of the I/O traffic from those systems that is completely unnecessary, so they don’t interfere with your SQL performance.

- Any customer that is on the core or host pricing model is able to deploy the software to an unlimited number of guest machines on the same host. If you are on per system pricing, consider migrating to a host model if your VM density is 7 or greater.

  3) Cap MS-SQL memory usage, leaving at least 8GB left over

- Perhaps the largest SQL inefficiency is related to how it uses memory. SQL is a memory hog. It takes everything you give it then does very little with it to actually boost performance, which is why customers see such big gains with our software when memory has been tuned properly. If SQL is left uncapped, our software will not see any memory available to be used for cache, so only our write optimization engine will be in effect. Moreover, most DB admins cap SQL, leaving 4GB for the OS to use according to Microsoft’s own best practice.

- However, when using our software, it is best to begin by capping SQL a little more aggressively by leaving 8GB. That will give plenty to the OS, and whatever is leftover as idle will be dynamically leveraged by our software for cache. If 4GB is available to be used as cache by our software, we commonly see customers achieve 50% cache hit rates. It doesn’t take much capacity for our software to drive big gains.

  4) Consider adding more memory to the SQL Server

- Some customers will add more memory then limit SQL memory usage to what it was using originally, which leaves the extra RAM left over for our software to use as cache. This also alleviates concerns about capping SQL aggressively if you feel that it may result in the application being memory starved. Our software can use up to 128GB of DRAM. Those customers who are generous in this approach on read-heavy applications get into otherworldly kind of gains far beyond 2X with >90% of I/O served from DRAM. Remember, DRAM is 15X faster than SSD and sits next to the CPU.

  5) Monitor the dashboard for a 50% reduction in I/O traffic to storage

- When our dashboard shows a 50% reduction in I/O to storage, that’s when you know you have properly tuned your system to be in the range of 2X faster gains to the user, barring any network congestion issues or delivery issues.

- As much as capping SQL at 8GB may be a good place to start, it may not always get you to the desired 50% I/O reduction number. Monitor the dashboard to see how much I/O is being offloaded and simply tweak memory usage by capping SQL a little more aggressively. If you feel you may be memory constrained already, then add a little more memory, so you can cap more aggressively. For every 1-2GB of memory added, another 10-25% of read traffic will be offloaded.


Not a customer yet? Download a free trial of Condusiv I/O reduction software and apply these best practice steps at


How to Recover Lost or Deleted Files BEFORE Resorting to Outsourced Data Recovery

by Gary Quan 1. November 2017 05:46

Here’s a nightmare scenario…a user accidentally deletes irreplaceable or valued files from a network share, and there is no way to recover the data because:

>The file was created or modified then deleted AFTER the last valid backup/snapshot was taken.

>There is NO valid backup or snapshot to recover the data.

>There was NO real-time recovery software like Condusiv’s Undelete® already installed on the file server

>Sending the disk to a professional data recovery center is COSTLY and TIME-CONSUMING.

What do you do? Well, you may be in luck with a little known feature in Condusiv’s Undelete software product known as “Emergency Undelete.” On NTFS (New Technology File system) formatted volumes, which is the default file system used by Windows, there is an unfamiliar characteristic that can be leveraged to recover your lost data.

When a file gets deleted from a Windows volume, the data has not yet been physically removed from the drive. The space where that file data was residing is merely marked as “deleted” or available for use. The original data is there and will remain there until that space is overwritten by new data. That may or may not happen for quite a while. By taking the correct steps, there is an extremely good chance that this ‘deleted’ file can still be recovered. This is where Emergency Undelete comes in.

Emergency Undelete can find deleted files that have not yet been over-written by other files and allow you to recover them. To increase your chances of recovering lost data, here are some best practices to follow as soon as the files have been accidentally deleted.

1. Immediately, reduce or do away with any write activity on the volume(s) you are trying to recover the deleted files from. This will improve your chances of recovering the deleted files.

2. Get Condusiv’s Undelete to leverage its Emergency Undelete feature.  Emergency Undelete is part of the Undelete product package.

3. REMEMBER: You want to prevent any write activity on the volume(s) you are trying to recover the deleted files from, so if you are trying to recover lost files from your system volume, then do one of the following:

a. Copy the Undelete product package to that system, but to a different volume than the one you are recovering lost files from. Run the Undelete install package and it will allow you to run Emergency Undelete directly to recover the lost files.


b. If you do not have an extra volume on that system, then place the Undelete product package on a different system, run it and Emergency Undelete will allow you to place the Emergency Undelete package onto a CD or a USB memory stick. You can then place the CD/Memory stick on the system you need to recover from and run it to recover the lost files.



Now if the lost files do not reside on the system volume, you can just place the Undelete product package on the system volume, run it and select to run Emergency Undelete directly to recover the lost files.

4. When recovering the lost files, recover them to a different volume.

These same steps will also work on FAT (File Allocation Table) formatted storage that is used in many of the memory cards in cameras and phones. So, if some irreplaceable photos or videos were accidentally deleted, you can use these same steps to recover these too. Insert the memory card onto your Windows system, then use Emergency Undelete to recover the lost photos. 

Emergency Undelete has saved highly valuable Microsoft Office documents and priceless photos for thousands of users. It can help in your next emergency, too.



Data Protection | Data Recovery | Undelete

Month List


<<  December 2017  >>

View posts in large calendar