9550 - high SSD disk queue length when plugging in external drive

Hi,

Anyone got any suggestions for this one. I've got a 9550, with 1Tb SSD. I also have a 2Tb external spinning disk that I use as a file history backup drive. If the external drive isn't connected, everything works perfectly. However the minute I plug in the external drive, the entire system becomes really unresponsive. It stays that way for ~5 mins, then goes back to normal & everything is fine till I reboot, then the same thing happens all over again. Nothing obvious in event log. Using resource monitor, the only thing I can see is that when the external drive is connected, the disk queue length on the INTERNAL SSD goes from ~0.5-1.5 up to 5+. Yet there's nothing spectacularly unusual happening as far as disk activity is concerned, and nothing obviously starts being read/written as a result of the external drive being plugged in - either on the internal or external drives. I even tried changing the external drive, in case it was a weird fault on the drive, but it made no difference. Any ideas how to troubleshoot?

 

Have you tested a different external enclosure? Most importantly, test using a different SATA-to-USB bridge controller. I've seen this type of behavior before with some cheap knock-off SATA-to-USB bridge controllers.

Also, test a different USB storage device (like a USB flash drive). This will test whether the problem is with your internal USB controller / driver on your laptop, or if it's with the external device(s) you're plugging in.

Also, test that drive on another system, and see if it has the same problem. However, be aware that even if the external USB drive works fine on another system, it still may have some weird incompatibility bug with your XPS 15

 

Have you enabled indexing on the external drive?
Have you enabled a OneDrive folder on the external drive?

 

Thanks for the replies both - no indexing, and no OneDrive on the external drive, purely file history. When i run performance monitor, there's essentially no traffic on the external drive at all, the only traffic is on the internal drive. I've tried 2 different external drives, and I've tried connecting directly to the laptop, or through the dock (TB16) - same problem in both cases.

 

Just as a followup, I've been running various performance monitoring, and you can see the effect just looking at the disk transfer rates. In the attached we're looking at c:, and you can see that the minute the external drive is attached, disk transfer drops, and stays low while the system is unresponsive, before picking up again a few minutes later. Whether this is a symptom or the cause, I don't know, but it's clear that attaching the external drive is doing something nasty to the system. Any suggestions welcome!