# Example output of a successful query smartctl -i -d megaraid,0 /dev/sda === START OF INFORMATION SECTION === Device Model: Samsung SSD 870 EVO 250GB Serial Number: S1234567890 Firmware Version: SVT01B6Q SMART support is: Available - device has SMART capability. SMART support is: Enabled
: Tells smartctl to talk to the RAID controller to reach physical disk
This should return lines like /dev/bus/0 -d megaraid,4 . In this case, 4 is your ID.
smartctl -a -d megaraid,0 /dev/sda
When using on a Dell server equipped with a MegaRAID (PERC) controller, you may encounter the following error:
This guide explains why this communication breakdown occurs, outlines how to accurately determine your physical drive layout, and details how to correctly address individual storage layers hidden behind hardware abstractions. Why Direct SMART Queries Fail on Hardware RAID Controllers
For MegaRAID/Dell PERC, the most reliable tool is storcli (successor to megacli ): # Example output of a successful query smartctl
To read the SMART data for the drive in the RAID array, use: smartctl -a -d megaraid,0 /dev/sda Use code with caution. For the second drive: smartctl -a -d megaraid,0 /dev/sda Use code with caution. Replace 0 with 1 , 2 , etc., for subsequent drives. Why This Happens (And How to Fix It Properly)
# Correct syntax to check disk with ID 0 on the first RAID adapter smartctl -i -d megaraid,0 /dev/sda
To fix the communication block, you must rewrite your instruction using the device type parameter: -d megaraid,N . The variable acts as a unique target coordinate matching the physical slot or Device ID managed by the hardware backplane. smartctl -a -d megaraid,0 /dev/sda When using on
To query the individual physical drives hidden behind your RAID array, you must explicitly instruct smartctl to pass its commands through the MegaRAID controller layer using specialized syntax. Why Standard S.M.A.R.T. Queries Fail on RAID
How to Fix "smartctl: open device /dev/sda failed" on Dell PowerEdge with PERC/MegaRAID
The error message occurs because RAID controllers like the Dell PERC series hide physical hard drives behind a virtual abstraction layer . When you run a standard smartctl command on /dev/sda , the utility only sees the "Virtual Drive" created by the controller, which does not support direct S.M.A.R.T. queries. The Solution: Using the -d megaraid,N Flag Replace 0 with 1 , 2 , etc