smartctl is a command-line tool used to control and query S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) data from hard drives and SSDs. It helps predict drive failures by reporting attributes like Reallocated Sectors, Reported Uncorrectable Errors, Temperature, and more.
smartctl -a -d megaraid,<N> /dev/sda
Where <N> is the Physical Disk ID (not the SCSI ID). N ranges from 0 to N-1, where N = number of physical drives behind the controller.
smartctl -a -d megaraid,N /dev/sda
If you are writing a script or noting this down for future reference, the clear syntax is:
| Component | Meaning |
| :--- | :--- |
| -d | Device Type Flag |
| megaraid | The driver for Dell PERC / LSI controllers |
| ,N | The physical disk index (0, 1, 2, etc.) | smartctl is a command-line tool used to control and query S
By ignoring the garbled "39" text and identifying the correct disk index, you will successfully bypass the "Device Open Failed" error and retrieve your SMART data.
Fix: smartctl "Open Device Failed" on Dell or MegaRAID Controllers
When running smartctl on a Dell PowerEdge server or any system using a MegaRAID (LSI/Broadcom) controller, you often encounter this error:Smartctl open device: /dev/sda failed: Dell or MegaRAID controller, please try adding '-d megaraid,N'. Where <N> is the Physical Disk ID (not
This happens because the operating system sees a virtual logical drive (the RAID array), but smartctl needs to talk directly to the physical disks hidden behind the controller. The Solution: Using the -d megaraid,N Flag
To bypass the virtual layer, you must tell smartctl which specific physical disk you want to inspect by providing its Device ID (represented as 1. Find the Physical Device ID (
You cannot guess this number, as it doesn't always start at 0. Use the storcli (or older MegaCli) utility to find the DID (Device ID). Command: sudo storcli /c0 /eall /sall show If you are writing a script or noting
What to look for: Locate the DID column in the "Drive Information" table. If your disk is in slot 1 and has a DID of 11, then 2. Run the Correct smartctl Command
Once you have the ID, run the command against the controller's device node (usually /dev/sda or /dev/bus/0). Cannot get smartctl working - Unix & Linux Stack Exchange
It sounds like you’re encountering the classic smartctl error when trying to access a physical disk behind a Dell PERC (MegaRAID) controller. The message you're referencing is essentially telling you to use the correct device syntax: -d megaraid,N.
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