How to check the RAID configuration on Linux/Unix systems

Linux based systems support both Hardware and Software based RAID systems. So there are times that we want to check the RAID configuration through the operating system. With Linux this is possible to analyze the configuration with the help of mdstat file.

So, to check the RAID configuration you can simply cat the following files;


  • cat /etc/mdadm.conf
  • cat /proc/mdstat

Once the above configuration is analyzed, you will end up with the following specific results;

  • md125 – RAID device file name
  • active raid10 – RAID type
  • sde3[3] sdb3[2] sdc3[1] sdd3[4] sda3[0] – RAID device named /dev/md125 made of five partitions (also known as “component device”)
  • [UUUUU] – Shows status of each device of raid member disk/partition. The “U” means the device is healthy and up/running. The “_” means the device is down or damaged

If you want to determine whether a specific device is a RAID device or a component device, you may execute below;

  • mdadm –query /dev/DEVICE
  • mdadm –query /dev/md125
  • mdadm –query /dev/md12{5,6,7}

If you want to see info about component device named /dev/sdd3, run:
Example: # mdadm –examine /dev/sdd3

Server 2012 Hang on Startup TiWorker.exe causing boot loop

The TiWorker (This is an automated scheduled task that comes pre-configured in Windows Server 2012 R2) process is related to the following services;

  • Windows Update service
  • TrustedInstaller.exe
  • Windows Modules Installer service

The symptoms for this issue that your Windows 8 or Server 2012 system runs slowly and applications lag. If you press CTRL+ALT+DEL and check the Windows 8 or Server 2012 Processes. Then you will see a process called tiworker.exe using around 80% – 90% of your CPU time. If you try and end this process the tiworker.exe automatically starts itself again.

After 30 minutes or so the issue will go as the tiworker,exe process will end. This process is used by Microsoft’s auto update services when downloading and applying updates to Windows 8 and Server 2012, it runs an applicability scan hence why the process will restart when you kill it as it will run until it has checked if there are updates for applications you are running.

To resolve the issues, 2 workarounds can be applied to the affected system (But there is not a confirmed fix for the issue)

  • Workaround 01 : Applying the hotfix from the Microsoft
  • Workaround 02 : Disabling the related services (Windows Update service / Windows Modules Installer service)