What causes USB backup processes to stall on my Mac running Sox 12.6.6?

johnsankey wrote:

John, the disk I've been using for Time Machine checks out 100%. I always format new USB sticks with a secure erase to make sure they are solid.

That is not enough. The only way to make sure the USB stick is not corrupting data is by making actual checksums from time to time to verify there have been no bit errors. As the others have mentioned, the quality of USB sticks is extremely poor and should never be used as the only backup and definitely not the only copy of any important data. All that secure erase told you was that there was no problem while performing that erase, but what about when you transferred data next time?

I utilized a non-Apple file system on some USB sticks so that I could easily check for bit errors.....and many USB sticks produce bit errors from time to time......some more than others. Unlike Hard Drives and SSDs which have built-in hardware to auto correct for some bit errors, a USB stick does not have that technology.

It turns out the problem with trying to copy an entire user directory is because it includes some sort of a copy of the Applications directory and I assume that includes the copy utility. I tried making a copy of the directory contents 1 level down excluding that Applications directory; it's worked fine and has everything I need to keep.

You will always have problems copying data from the macOS user account you are logged into because the data within that account is constantly changing. Copying data while not logged into a user account is a bit more difficult/complicated.

@Zurarczurx's suggestion for CCC is an excellent one.

The problem is really caused by Time Machine. The clock for it in the top right corner used to rotate while it was working; when it stopped the backup disk could be dismounted. That feature was removed a while back so we now have to use a terminal command to find out if it's finished. There's something wrong with the command because when it says TM is finished, disk dismount fails saying a process is still using the disk (only TM ever uses that disk)

Bad assumption. Spotlight may be indexing the drive. Spotlight is notorious for not letting go when a user attempts to eject a drive. Very frustrating. See my other post where I show how to identify what app/process is accessing a drive when it cannot be ejected:

Cannot eject USB drive due to unknown program -- HWTech - Apple Community

A backup you can't trust is no backup at all, so I'm going to have to work out a regular procedure using USB sticks.

USB sticks for a backup is nearly the same as no backup. At least use a standard Hard Drive or SSD.

If you don't like Time Machine (it does have issues & limitations for some people), then check out Carbon Copy Cloner as mentioned by @Zurarczurx as it is a great app from a developer who has a great reputation. CCC has been available for decades.

If you're just doing a straight copy then use rsync in Terminal or one of the GUI apps for it. I use backuplist+ (free). I think CarbonCopyCloner does too but I've never used it and don't know if it's free.

The advantage of this method over just dragging in Finder is that rsync can still copy across files that are in use, locked or have access restrictions. You can also stop it at any time and it will just continue and only copy what wasn't copied last time. rsync in Terminal has about a million switches and can be daunting, hence the recommendation for a GUI.

Long term, I agree with John Galt - a single backup (TM or vanilla copy) is better than none, but you should have more than one and at least one away from home. I keep one TM disc and one rsync disc in a metal bike shed at the bottom of the garden. Precious photos are also on a disc at my folks' a few hundred miles up the road.

That simplifies the answer greatly. The USB "stick" is no good. Throw it out.

Connect and use other storage devices with Mac - Apple Support

The usual method is to use Time Machine, and ideally more than just one backup drive. Any device can fail at any time, including backup drives.

USB flash drive quality tends vary all over the map. You probably have a bad one.

If you expect backups to be reliable use a supported backup device. Please refer to Backup disks you can use with Time Machine - Apple Support. USB "sticks" are notably absent from that list.

I tried to use USB flash drives with Time Machine. They failed every time. Don't use them.

It also occurred to me the capacity of that USB "stick" is inadequate. Apple's recommendation is to use a backup disk with at least twice the capacity of the source volume. If you are going to have any hope at all of using any backup disk consider that amount a minimum.

Back up your Mac with Time Machine - Apple Support

I also reiterate my recommendation to avoid using USB flash drives, or SD cards for that matter.

johnsankey wrote:

Thank you HWTech. I wasn't aware of Spotlight since it doesn't appear in any app or utilities listing I've seen. Since I obviously haven't needed it in over a decade, I unchecked all the files it could index.

The instructions in the following Apple article should be all that is needed to prevent indexing of a particular volume or folder:

Prevent Spotlight searches in files on Mac - Apple Support

Instructions on how to use Terminal to turn Spotlight off are fouled up

macOS has changed a lot in recent years so lots of former instructions may no longer be valid.....assuming those instructions were actually even proper back in the day. There is a lot of bad information on the Internet.....just because something can be done, doesn't mean it should be.

by the recent change of shell to zsh - it doesn't accept my old password and announces that 'this attempt will be reported'!

The change of default shells should have no bearing on anything unless you are utilizing a Bash or Zsh specific option. Even then, it is trivial to switch between shells.

To whom? But that belongs in another thread...

A notice is sent to the system mail account accessible through the command line "mail' utility (the *nix old school mail utility, not the macOS GUI Mail app).