If you see that your LSI RAID array has a failed disk, but you’re not sure which physical disk in the machine it is, use the MegaCli command line utility to flash the drive’s LEDs:

Command syntax:

MegaCli64 -PdLocate <-start|-stop> -physdrv[<enclosure#>:<disk#>] -a<adapter#>

In this example, we will locate disk 0 on adapter 0 (the first disk in the array):

$ MegaCli64 -PdLocate -start -physdrv[252:0] -a0

Once you’ve found the drive with its activity LED blinking, you can stop it by typing:

$ MegaCli64 -PdLocate -stop -physdrv[252:0] -a0