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.
Fixing the "smartctl open device /dev/sda failed: DELL or MegaRAID controller" Error
: Do not trust the VALUE field across different disk vendors; always look at the RAW_VALUE column. The way vendors normalize attribute values differs significantly. The RAID controller does not expose the physical
sudo smartctl -a -d cciss,N /dev/sda
The input string is currently and slightly confusing as a search query. It reads like a voice assistant's incorrect transcription of a technical support interaction. for d in 0 1 2 3; do
for d in 0 1 2 3; do smartctl -H -d megaraid,$d /dev/sda; done
RAID volumes (virtual disks) will appear with the vendor name LSI or DELL and Type: Direct-Access . Physical disks attached to the controller may also be listed, with their channel and ID information. do smartctl -H -d megaraid
Alternatively, use the Dell PERC/MegaRAID utility to list physical drives: MegaCli -PDList -aALL | grep "Device Id"
The error message explicitly tells you what to do. You must:
The command reaches the virtual device exposed to the operating system.
When you run the command smartctl --all /dev/sda (or similar) and encounter the error "smartctl open device dev sda failed dell or megaraid controller," it typically indicates that smartctl is unable to access the disk directly due to the presence of a RAID controller, specifically a Dell or MegaRAID controller. This controller abstracts the physical disks, making it challenging for smartctl to communicate with the disk directly.