Time Machine error 19 - backups failing then completing

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Level 2

152 points

Time Machine error 19 - backups failing then completing

My Time Machine backups consistently say "Backup failed with error: 19" -- but the backups then proceed to complete successfully. I only know about the issue because I saw the errors in Console.

I back up to 2 external HDs, and this happens with both of them every time (both with hourly and manual backups).

I recently upgraded to Mountain Lion; I don't know if it was happening before.

I tried changing the name of my computer in System Preferences / Sharing (per Pondini's advice to someone else's posting), but that didn't help. (Nor did using a USB cable instead of FireWire.) I also tried restoring an item from a backup, and it worked….

My question: What should I do? Of course it's not good to have errors, but if the backups are working, should I still do a full reset of Time Machine or something?

I started this discussion originally under a title that didn't describe the problem very well -- I later wanted to change it but couldn't. That discussion is at:

https://discussions.apple.com/thread/4982163?answerId=21833059022#21833059022&ac_cid=op123456#21833059

Thank you.

iMac

Posted on Apr 22, 2013 3:54 AM

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Answer 1

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Pondini

Level 8

38,863 points

Apr 23, 2013 8:46 AM in response to DonnaR

DonnaR wrote:

. . .

I back up to 2 external HDs, and this happens with both of them every time (both with hourly and manual backups).

If I understand your setup and procedure correctly, this is not a problem.

You have both drives set up as TM destinations, right? If so, Time Machine is trying to alternate backups between the two.

If both are available, it will back up to one; then an hour later, the other, and continue "rotating" between them. If not, it will back up to the one that is avalable.

Each hour, it will try to back up to the one that's "due" for a backup. But if that one isn't available, it will send the "error 19" message to the log, and switch to the other one automatically.

So, if you're only connecting one drive at a time, for a week, then TM will almost always try to back up to the one it hasn't seen in a while, send an "error 19" about it, then back up to the one that is available.

The backup will only fail if neither drive is available (but it will send a message if it hasn't been able to back up to a particular drive in 10 days).

In your situation, it may appear to be a problem, but this "rotation" scheme actually allows 3 different scenarios:

• "Dual" backups in one place: Two drives (directly-connected or on a network) always available, such as with a desktop Mac. Time Machine simply alternates between the two.

• Backups in two places: Someone who carries a laptop from home to work, and wants to back up in each location. Time Machine will back up to whichever destination is avaialble.

• Your setup of connecting one drive for a week, then swapping with another.

If I've misunderstood your setup, please clarify.

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Answer 2

Pondini

Level 8

38,863 points

Apr 23, 2013 9:09 AM in response to DonnaR

I should add, while I'm certainly a proponent of redundant backups, having only two made by the same backup app may not be the best, safest strategy.

Most likely, the reason you're making an extra set of backups is because you know that all hardware fails, sooner or later, and you want to be protected against either of those drives failing (or getting dropped, stolen, erased in error, etc.).

While Time Machine is quite reliable, no backup app is absolutely perfect. They all have occasional failures -- sometimes of the app itself, sometimes a problem with the data being backed-up, sometimes because a user doesn't fully understand it. Whatever app you're using, I'd advise using a different one for another set of backups.

You might want to review Time Machine - Frequently Asked Question #27 for a bit more explanation and some suggestions.

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Answer 3

DonnaR Author

Level 2

152 points

Apr 23, 2013 12:17 PM in response to Pondini

That was it! (I figured you were right, but checked in Console just to make sure.) I can't thank you enough -- that saved me from doing anything further to try to "fix" something that wasn't broken.

I'd searched online for error 19 before posting, but didn't find anything that indicated it might not be a problem. Now hopefully others can see this....

Of course, you're also right about not depending on only one backup or means of backing up. To what you wrote above, I'd add that there's an additional risk of having everything in one location (e.g., fire), so I also use an Internet backup service.

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Answer 4

Pondini

Level 8

38,863 points

Apr 23, 2013 5:18 PM in response to DonnaR

DonnaR wrote:

That was it! (I figured you were right, but checked in Console just to make sure.)

Good for you! 😉

For what little it's worth, I've filed a Bug Report with Apple, for sending a misleading message to the log ("Backup failed with error: 19") in such cases, since the backup didn't actually fail.

Instead, TM should send something like: "Disk <name> not available; trying to back up to the next disk."

Don't hold your breath . . .

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Answer 5

rei_vilo

Level 1

20 points

Sep 9, 2013 1:09 AM in response to Pondini

Thank you for the explanations.

I also have two backups for my MacBook, one portable HDD and a TimeCapsule.

The only problem with the -19 error is that TimeMachine backs-up the entire disk.

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Answer 6

Pondini

Level 8

38,863 points

Sep 9, 2013 5:11 AM in response to rei_vilo

rei_vilo wrote:

Thank you for the explanations.

I also have two backups for my MacBook, one portable HDD and a TimeCapsule.

The only problem with the -19 error is that TimeMachine backs-up the entire disk.

On which disk? It will do a full backup to each disk (when it can), then only "incremental" backups thereafter of what's new or changed.

Please clarify exactly what's happening.

A clue may be lurking in your logs. Use the widget in #A1 of Time Machine - Troubleshooting to display the backup messages from your logs. Locate the backups in question, then copy and post all the messages here. That should help us figure it out.

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