You cannot guess this number, as it doesn't always start at 0. Use the storcli (or older MegaCli ) utility to find the (Device ID). Command : sudo storcli /c0 /eall /sall show
To bypass the virtual layer, you must tell smartctl which specific physical disk you want to inspect by providing its (represented as 1. Find the Physical Device ID ( You cannot guess this number, as it doesn't
This happens because the operating system sees a (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 You cannot guess this number