How to make SCSI enclosure LEDs blink?

Question

I have a SCSI enclosure (supermicro BPN-SAS-825TQ) residing on Ubuntu 16.04.

Is there an sg_ses (or sg_senddiag or other) command I can send to the enclosure, that will make the Rear LEDs blink, even if there's no disk in the enclosure?

Answer 1

After having spent an hour trying to figure out how to get the correct indices for sg_ses command to work, I ended up using encled utility from this project https://github.com/amarao/sdled which has much more intuitive interface. It's a python script, so no compilation required, you can just download it and use right away.

Encled - utility to change location / fault LED for enclosure.

"location" and "fault" is just how LEDs are named. They both may actually be represented by a single LED, but locate would make it blink, while fault would just turn it on continuously.

Note: the project has both sdled and encled utilities — you want the latter.

Examples:

• List devices and LED status on them: ./encled
• Turn on "locate" LED on /dev/sdbe device: ./encled sdbe locate
• Turn off all LEDs on all devices: ./encled all off

Answer 2

That depends on your particular backplane being visible to the host system (it should be visible as SCSCI device under lsscsi -g). In general, to turn on ID LED in a slot 1 of the /dev/sg4 enclosure you should issue

sg_ses --dsn=1 --set=ident /dev/sg4

and, alike, to turn it off

sg_ses --dsn=1 --clear=ident /dev/sg4