Time Machine Backup to another Mac

[davegoody]

Hi all.

After many years of posting and helping other Mac users, it's my turn for help ! - Only second time I have asked for help here, so thanks in advance.

My Time Capsule died last week, and now I have a Mac Mini set up as a PLEX server, it's on all the time.

Both my 5k iMac, and the Mac Mini (and all other Macs in the household) are running Catalina (10.15.1) with no major issues.

Have set up a Hard Drive (formatted to Mac HFS+ Journaled) on the Mac Mini, it's set to share using SMB and AFP, have a user set up for read/write access, I can mount the share and write to it from the iMac no problem. It is shared (in advanced) as a Time Machine Destination)

The issue I have is that when I set it up as a Time Machine destination, it accepts the login details but when the backup is attempted, I get the error that it couldn't backup to the destination and The network backup disk could not be accessed because there was a problem with the network username or password. You may need to re-select the backup disk and enter the correct username and password.

The username and password ARE correct, and I have cleared entries from the system keychain but pulling my hair out !

Some help would be appreciated before an expensive Hard Drive goes flying through the window. The HDD works fine locally on USB etc......

 

[Weaselboy]

https://support.apple.com/en-us/HT202784#mac

Are you doing this step from the Apple help document?

5. From the Advanced Options dialog, select ”Share as a Time Machine backup destination.”

 

[davegoody]

Yes - I mentioned that in my post it’s so frustrating - I work in the industry and give loads of advice to people, but this one is stumping me, I can mount the drive / share on the iMac using the same credentials and can drop files in no problem- it’s just time machine that has the problem ....... there must be something I am missing lol

 

[chabig]

You need to share the drive as a Time Machine backup destination per the instructions. The client computer will not mount the backup volume.

 

[davegoody]

As per my initial question, it IS set up as a Time Machine Backup destination, exactly as per the instructions, and exactly as I have done COUNTLESS times. The Client computer can, and always has been able to mount the backup volume (useful for testing) as it's shared from the "server" using SMB and AFP, with the user assigned read/write access, and with the tick box under "advanced" for share as a time machine destination ....... so it's all right, but still gives me the error as referenced by my original post. Appreciate the response, but i HAVE met all the pre-requisites which is why this is so annoying.

 

[chabig]

Yes, but if shared correctly, the client machine won’t mount the drive, so something is amiss. Maybe you should turn off sharing on the server and set it up again.

That said, so we don’t back and forth trying to help, can you post a picture of your Sharing settings?

 

[ApfelKuchen]

If the sharing settings are by-the-book, what else might affect this "failure to communicate?" What else might break the network connection/login? Have you looked at Energy Saver settings (Wake for network access, prevent computer from sleeping automatically...)?

 

[davegoody]

Thanks for the above assistance. I removed the share (again) and re-shared it (with EXACTLY the same settings) - as per Chabig above - and ......... it's working. What's really odd is that I have done this three times now and each time it didn't work. Chabig you are obviously my lucky charm. Really appreciate the responses guys, that's what makes the MacRumors forums so great. Maybe some time I will be able to return the favour..... Have a good evening (or whatever time it where you all are).

 

[chabig]

I used to need to do that after rebooting, but that was Mojave. I haven’t had to do it since Catalina. I never understood it but I’m glad you tried and I’m glad it worked.

 

[davegoody]

Whatever happened to the Apple mantra of "it just works" ? - That's a rhetorical question of course, but I am finding QA at Apple with recent OS releases has been awful. More so with iOS / iPad OS.

 

[ApfelKuchen]

Whatever happened to the Apple mantra of "it just works" ? - That's a rhetorical question of course, but I am finding QA at Apple with recent OS releases has been awful. More so with iOS / iPad OS.

It's really hard to say. My feeling is that things work remarkably well. We sometimes lose touch with just how many layers and threads of complexity have been added over the years. Billions and billions of bits and bytes, and all it takes is one stuck settings bit or a statistically rare concatenation of conditions...

Of course, when something does go wrong that's no consolation, and the solution to the problem (often a reset/restart of some sort) gives little hint as to the cause - just wipe the slate clean and start over. And even if we knew the cause, it's unlikely there's a preventative measure we could take to avoid a recurrence. Like lightning, the same problem may never strike a particular user again. It's nearly quantum-mechanical.

So we do what we can. We weigh the costs and benefits, and decide whether the benefits of the added complexity (say, backing up across a wireless network rather than to a hard-wired local drive) outweigh the difficulties of troubleshooting the potentially complex problems that will occasionally arise.

 

[davegoody]

That's very fair. I have been in IT for more years than I would like to mention, and to be honest, the incompatibility issues with Windows and drivers is (still) far worse than any of the issues Apple have had. I just think that sometimes QA is not as good as it should be. We do pay a premium for our Macs (and though the cost of the OS is "free" it still ought to be a better experience). Mojave was a lot more stable and less buggy than Catalina (by far) - even with it's early point releases..... but NOTHING would make me move from the Mac, if we can't vent here, where can we ? - Thanks (again) to all who helped in this case..... Been long long week this week.

 

[johne999]

I have searched the 'net for a solution to this problem, exact same issues, I also checked every proposed solution. I go through the select process (by the way i have been using the same drive mapping for time machine for 6 years no issue until now). I removed and added, drives, passwords, permissions, everything, but after selecting and entering credentials, all seems OK until actual back up starts, then I get the dreaded message

"The network backup disk could not be accessed because there was a problem with the network username or password. You may need to re-select the backup disk and enter the correct username and password"

At my wits end....

Machine to back up 12.1 (MacBook Air), machine with mapped drive for time capsule 10.6 (Mac Mini).

 

[chabig]

I found two possible solutions to try through an internet search:

1. "Appears the Keychain for this process was corrupted. Deleting the keychain associated with the share drive and reselecting the drive via Time Machine preferences appears to have resolved it."

2. "Try setting the timemachine user's password to alphanumeric characters only."

 

[RockinRico]

Thanks for this thread, it pointed me to the right direction.

The step that solved my problem was to also turn on AFP file sharing on the server (link to original answer).

 

[david95966]

I was having some of the same problems. Here is my logic for fixing it. I was already using the same username and password for all macs because that simplifies everything, but I happen to trust those who I live with. I erased my external drive. I formatted APFS (but I'm not sure I needed that). I deleted all shared drives, but nothing from keychain, just from sharing. I added the internal boot drive to sharing then added the external drive. I tested the new drive by making sure I could see the content remotely. I added the external as a TM destination. Once that was all working, from the remote mac, the TM login into server process worked. So nothing fancy, and not too hard.