You cannot simply use /dev/sda . You must find the index number (N) of the physical drive behind the controller.
Look closely at the or the Slot Number . If the slot number is 4 , your flag will match that assignment: -d megaraid,4 . Step 3: Test and Verify S.M.A.R.T. Queries
The controller bundles multiple individual drives into a structural pool (Drive Group) and projects one or more virtual "Logical Volumes" to the operating system.
The smartctl utility itself can scan for available devices behind RAID controllers. Run: You cannot simply use /dev/sda
The RAID controller does not expose the physical disks through the standard SCSI layer. This is common with entry‑level RAID cards or those operating in a “simple” RAID mode.
: /dev/sda -d megaraid,0 -a /dev/sda -d megaraid,1 -a Troubleshooting Persistent Failures If you still see failures after adding the -d flag: Error with smartctl on Dell/Megaraid · Issue #660 - GitHub
for i in 0..30; do echo "Testing megaraid,$i" sudo smartctl -i -d megaraid,$i /dev/sda done If the slot number is 4 , your
Under this output configuration, your primary disk targets correspond to IDs 0 and 1 . Step 2: Query the Specific Physical Drive
Run the native device discovery scan command provided by Smartmontools: sudo smartctl --scan Use code with caution.
This approach is particularly effective for SAS/SATA drives hidden behind SAS-capable Dell PERC controllers. sudo smartctl -a -d sat+megaraid,0 /dev/sda Use code with caution. Method 2: Verifying with storcli (Best Practice) For accurate identification, install and use storcli : The smartctl utility itself can scan for available
Always prefix your commands with sudo or run them as the root user. Additionally, ensure your user is a member of the disk group on some distributions.
:You need to find the correct value for N (the Device ID). You can automatically list all detectable physical drives and their IDs by running: smartctl --scan