Summary
Trying to clone and older ssd to a newly purcahsed one. The new one was consistently ejected before completion during the process using first the finder copy/paste and then trying the cpio command. Maybe related to some very deep folders.
The only solution that’s working is the use of the “rsync” command.
Detail
Got a new “SanDisk Extreme Portable SSD.” First task was to clone an existing older SanDisk SSD. First I tried copying folders using the finder. The new SSD was consistently ejected prematurely. Next I tried a combination of "find <some folder[s]>|cpio -pdmv. Same issue. I did all the usual stuff:
Swapping cables
Connecting the ssd(s) directly to my macbook air instead of my apple studio
etc.
After a lot of experimentation, it seems that the cpio command is the issue. I used the rsync command instead and things are working well.
Remaining Question
I can forgive the cpio command, but what about the copy paste in the finder? How do I explain that?
“When the Finder copies files, it first catalogs all files to be copied and then treats the copy process as one all-or-nothing copy routine. Because of this, if you copy multiple files and there is an error in accessing one, then the system will cancel the entire process and revert the system to its state before the files were moved.”
We can’t rule out a flaw with the new SSD, I guess. But as you are familiar with the terminal commands, perhaps try the copy command “cp”. The “man cp” gives all the options.
The only tests that come to mind are trying to copy a similar amount of files from the computer --not the old SSD-- and see what happens just in case the combo of both SSDs is somehow raising problems in the USB interfaces itself, and keeping an eye on Console to watch for kernel errors, which i’m pretty sure you’ll spot because an automatic ejection means some critical error.
I believe at the end of your investigations you’ll find a physical error. I’d return the drive.