Apple User Help

How to cancel a program’s large upload happening via nsurlsessiond?

I launched a program (Apple’s Feedback Assistant) on Big Sur that uploads files to Apple via nsurlsessiond. I neglected to observe that one of the files was >500MB, and after I submitted it, I wanted to cancel the upload. Note that the upload proceeds in the background (i.e., even after I quit Feedback Assistant).

I cannot find any user interface to cancel it. Meanwhile, the upload kept running in the background for hours.

Following the advice at How to know what nsurlsessiond is downloading I ran

sudo lsof | grep nsurl

and was able to spot what I believe is the large upload file at:


(where XXX represents a long string of characters and/or hex digits).

I cannot access the enclosing folder, even if I give Full Disk Access to Terminal or enable the root account and log in to that. I keep getting "Operation not permitted". (I haven’t tried disabling SIP, which I am reluctant to do.) Even if I could get access to the folder, it is only a guess that deleting the file to be uploaded would give the desired result – it might also cause nsurlsession to stop working altogether, which would be bad.

I was eventually able to stop the upload, by using Little Snitch to identify the endpoint of the upload ( and deny that.

It’s still waiting to keep sending that big file, though. If I reboot, it’s still there. If I turn off the rule blocking that domain, then a little while later the upload starts up again.

I’d like a better way to cancel that upload and see that half-gigabyte file go away.

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