Orange Flashing USB Light after External Drive Removal

[Rodrigo Aluizio]

Hi there. Just reporting, once this does not cause any sort of system warning or malfunctioning of my NAS. Here is the short story. Once I plug in an usb external HD the usb led becomes blue and the drive is accessible. To unmount it I go to the Disk Utils and eject the drive and I receive the message saying that I can physically remove the drive. However, after physically removing the portable HDD the usb led flashes orange and only a reboot seems to stop it. Testes a few times and it always happens.

As I said before, no issues attached to the orange led, at least none that I became aware of. If I plug back the USB HDD, it mounts and works, the led gets blue, but the orange still flashes over it. My NAS is a DNS-320L Rev A3 with RC6.

[João Cardoso]

On Monday, 22 May 2017 13:01:31 UTC+1, Rodrigo Aluizio wrote:

Hi there. Just reporting, once this does not cause any sort of system warning or malfunctioning of my NAS. Here is the short story. Once I plug in an usb external HD the usb led becomes blue and the drive is accessible. To unmount it I go to the Disk Utils

You can also press the USB front button to unmount the disk, but you will not receive any feedback that the drive is or not ready to be removed.

When the USB button is pressed the disks orange leds start to blink and stop blinking when the button is released.

I can't reproduce the issue on a DNS-320L-A1 box, can it be that your USB button is stuck?

[Rodrigo Aluizio]

Unfortunately it’s not a stuck button, just checked it. And I guess that if it was the case the light would flash even without a USB HDD present or removed.

[João Cardoso]

On Monday, 22 May 2017 22:17:36 UTC+1, Rodrigo Aluizio wrote:

Unfortunately it’s not a stuck button, just checked it. And I guess that if it was the case the light would flash even without a USB HDD present or removed.

Yes, you are right.

I glimpse through the code and can't find the reason why that happens for you... ah, there are two kinds of blinking, a fast one, on/off every second or so (as when you press the USB button for a couple of seconds, e.g.) and a slow one, a slow flash on every 2 seconds; the latter happens when the drive is sleeping/standby/spin-down and happens for all drives, either internal or USB.

As some/most USB disk adapters don't report if the USB drive is spinning or not, that can be the issue as some heuristics (number of read/writes) are used to try to determine if the USB drive is in standby).

Probably the culprit is 'sysctrl'. Can you stop it using the command 'rcsysctrl stop' and try to reproduce the issue? Don't forget to restart sysctrl after completing the tests, as it controls other things in the box (fan speed, e.g), using 'rcsysctrl start'.

You have a DNS-320L-rev-A3, and I have a DNS-320L-rev-A1.

Thanks

[Rodrigo Aluizio]

Mine is the fast one. And you are right stoping sysctrl also stops the LED odd behavior. No flashing orange light after HDD removal.

[João Cardoso]

On Tuesday, 23 May 2017 22:46:51 UTC+1, Rodrigo Aluizio wrote:

Mine is the fast one. And you are right stoping sysctrl also stops the LED odd behavior. No flashing orange light after HDD removal.

OK, now I can reproduce it, but I have not an easy solution for that.

The issue happens when there is no activity (reads or writes to the USB disk) for a time longer than the set spindown timeout (Disk->Utilities); as some/most USB disk adapters don't support a user set spindown, nor give a disk spindown status, sysctrl tries to force the spindown and assumes that it was successful, starting the USB orange led in the slow "beacon/pharos" mode. If the USB drive is ejected in this mode, sysctrl doesn't know that and continues flashing the led.

Notice that the orange led is already in beacon mode even when the disk is attached and the blue led is on, you have to look carefully to see it blinking.

To avoid the issue, you can try to read or write any file to the disk before ejecting the drive, for it to leave the beacon mode first.

Another possibility is to set the USB spin down timeout to zero in Disk->Utilities (probably that should be the default)