Performance on degraded RAID 5 array, rebuilding performance too.

[RobinsonUK]

Hi,

We have a small 3 x 6TB disk raid 5 array on a workstation in Windows 10 (Pro, not a server) using Intel RST, with the array created on the bios screen (MSI), and did an experiment to see what the rebuild performance was like. We disconnected one of the drives to send the array into degraded state in order to do this.

We noticed two things: (1) when in the degraded state, the drive use went from about 10-20% to 100% in Task Manager (this is Windows 10). Our software was often failing to write its streams to the drive because of this, (2) when we reconnected the disconnected drive, the array went into the "rebuilding" state, which was good except this was also using 100% of the drive, so again our software more often than not was failing its writes.

I have two questions therefore: (1) what is going on with the degraded array such that drive use is 100%, (2) what is going on with the rebuilding array such that drive use is 100%. A third question would be, whatever it's doing, can we cap it so that our software continues to function during fail/recovery of a drive?

Thank you.

[Sebastian_M_Intel]

Hello RobinsonUK, 

Thank you for posting on the Intel® communities.   

So we can better assist you, we would like to have more details from your system, please provide the following: 

1. Run the Intel® System Support Utility (Intel® SSU) and attach the report generated:  

• Open the application, check the "Everything" box, and click on "Scan" to see the system and device information. By default, Intel® SSU will take you to the "Summary View".   
• Click on the menu where it says "Summary" to change to "Detailed View".   
• To save your scan, click on "Next", then "Save".   
• Use the option under the reply window to attach the report to the thread (Drag and drop here or browse files to attach).  

2. Provide the System Report for Intel® Rapid Storage Technology. 

3. What type of software are you using for the rebuilding? Is it Intel® Rapid Storage Technology (Intel® RST) or Intel® Rapid Storage Technology Enterprise (Intel® RSTe)? If not, are you using another third-party tool for this?  

Regards, 

Sebastian M  

Intel Customer Support Technician  

[Sebastian_M_Intel]

Hello RobinsonUK,  

Were you able to check the previous post and get the information requested? Please let me know if you need more assistance.   

Regards,  

Sebastian M  

Intel Customer Support Technician  

[Sebastian_M_Intel]

Hello RobinsonUK,  

We have not heard back from you, so we will close this inquiry. If you need further assistance or if you have additional questions, please create a new thread and we will gladly assist you.  

Regards,  

Sebastian M  

Intel Customer Support Technician