Thinkpads Forum

Seems to be several opinions on this as I Google, so thought to ask you all here.

Lenovo P51S with Ultradock. Two USB hard drives attached to the dock. Both set for "Quick Removal" in Device Manager.

DO I need to "safely remove" these drives before hot undocking and docking?

Appreciate your thoughts.

You never actually "need" to "safely remove" any USB devices on modern operating systems. Doing so merely "guarantees" that there will be no data loss, because it will force-flush all pending operations. "Optimize for quick removal", as far as I remember, disable write caching, so the chance of data loss is already diminished.

My rule of thumb with USB devices is to give them 5-10 seconds after any transfers are completed before disconnecting them - this should guarantee that things have settled.

Of course, if you set up you drives for ongoing background backup operations, you don't really know when a transfer is in progress; in this case, I would recommend using the "safe removal".

Thanks. I am finding even a bit stranger. Unless i am missing something, to safely remove when docked you still need to disconnect the USB 3.0 cable and do one at a time. Its not like a direct connection to the computer. If I could "safely remove" without physically detaching cables I would try. For now, I think I have to test an undock and redock without and hope I don't lose any data. Drives are usually idle and I am aware when they are being used.

Did not quite work as hoped.

Undock, no issues. Both drives were idle.

Redocking found only the second drive and Windows said a USB device could not be recognized. I unplugged it, replugged and found and working.

Any idea why that would happen?

Seems the USB Root Controller may have powered down on battery. Changed setting and checking that now. Makes sense if so.

Got it. Loose USB 3.0 port on the docking station. Different port works fine.