This issue typically arises because smartctl attempts to scan /dev/sda as a standard, standalone SATA or NVMe drive. However, on a system equipped with a hardware or an LSI MegaRAID card, /dev/sda is actually a logical virtual disk managed by the controller firmware. The operating system cannot see the underlying physical drives directly, which blocks the standard S.M.A.R.T. commands.
/dev/sda -d megaraid,0 # /dev/sda, Physical Disk 0 /dev/sda -d megaraid,1 # /dev/sda, Physical Disk 1 /dev/sda -d megaraid,2 # /dev/sda, Physical Disk 2
One will fail (non-existent drive) or return info for the correct disk. This issue typically arises because smartctl attempts to
EID:Slt DID State DG Size Intf Med 252:0 7 Onln 0 465.25 GB SATA HDD 252:1 6 Onln 1 465.25 GB SATA HDD 252:2 5 Onln 2 74.0 GB SATA SSD 252:3 4 Onln 2 74.0 GB SATA SSD
Logging, metrics, and UX
After running smartctl -a -d megaraid,0 /dev/sda , you might see:
The error occurs because standard smartctl commands cannot "see" through a Dell PERC or MegaRAID controller to the individual physical disks. To fix this, you must specify the raid type and the physical disk's ID using the -d megaraid,N flag. How to Fix the Error To successfully query your drive, follow these steps: commands
for pd in 0..15; do smartctl -H -d megaraid,$pd /dev/sda &>/dev/null; if [ $? -eq 0 ]; then echo "PD $pd OK"; else echo "PD $pd missing or error"; fi; done
When monitoring hard drive health on enterprise hardware, running into the error is a common rite of passage. To fix this, you must specify the raid