Controlling drive LEDs on a HP DL380e G8

Having discovered ledctl via Physically Identify the failed hard drive I've been trying to use it indicate a drive to pull from an HP DL380e G8 server running Proxmox, but ledctl locate=/dev/disk/by-id/... does nothing. The blue locate light on the LFF caddy stays resolutely off.

A ledctl -L successfully shows the SAS/SATA controllers:

# ledctl -L
/sys/devices/pci0000:00/0000:00:1f.2 (AHCI)
/sys/devices/pci0000:00/0000:00:01.1/0000:07:00.0 (SCSI)

I've confirmed that the disks are on those controllers:

# ls /dev/disk/by-path/ | grep -v part
pci-0000:00:1f.2-ata-6
pci-0000:07:00.0-sas-phy0-lun-0
pci-0000:07:00.0-sas-phy1-lun-0
pci-0000:07:00.0-sas-phy2-lun-0
pci-0000:07:00.0-sas-phy3-lun-0
pci-0000:07:00.0-sas-phy4-lun-0
pci-0000:07:00.0-sas-phy7-lun-0

It appears that the LSI SAS2308 controller supports SFF-8485 SGPIO, so that shouldn't be a problem, but there was still some suggestion that I might need an sgpio package to get it ledctl to work. However I can't any details of specifically which package I need or whether it needs any configuration.

The answers on other questions suggest it just works out of the box, but these may assume we are using the controller in RAID mode rather than JBOD^†.

^{† This machine was bought as a ZFS file server host.}

Looking through the issues at the Github intel/ledmon issues it looks like there should be some activity in /var/log/ledctl.log when ledctl is run, but on my system all I can see there are logs of attempts to run ledctl without arguments:

# ledctl locate=/dev/disk/by-id/...
# cat /var/log/ledctl.log
May 19 14:08:53   ERROR: missing operand(s)... run ledctl --help for details.

The only other thing IO can think of is that the backplane used by HP doesn't support addressing the LEDs this way.

So,

• Is it possible to use ledctl to control the LEDs on an HP DL380e G8 8xLFF backplane?
• If so, how?
• If not, is there any other way to do what I want?