Using the sas2ircu utility from LSI, we can blink the drive LED to help ID the failed drive correctly. Of course this requires a LSI card. Some LSI cards may need to use the sas3ircu utility instead. There have been some reports from the interwebs that this utility failed to blink the correct drive, but I have not experienced this myself.
As always use the supercomputer between your ears to ensure the physical serial and the serial reported by the system match, etc etc.
Back to the sas2ircu utility in a moment. We need to first acquire the serial number of the failed disk. For a system that is multipath, we can find the actual dev names by running the following to locate a disk in the fail state:
Now we can see da16 is failed. Time to get the serial number of that disk. Or da43. they are the same just multipaths.
Save that serial number for the next step.
Smartctl also outputs other useful information about the drive, statistics, etc. Worth checking out, but not relevant here.
Next, we can display the disks attached to one of those controllers. Be sure to input the correct serial number in the grep command:
Get the enclosure and slot # of the failed drive and turn the led on:
Turn the led off:
NOTE: If you are replacing a disk that is multipath, e.g. you see something like the following when you offline and remove a disk, ensure that the LED above is OFF or GEOM_MULTIPATH will not pickup the new disk as multipath. See the below log for what happens when a disk is inserted with the LED blinking Vs not blinking: