Time Capsule: "Backup Disk Not Available”

Is using of afp protocol the probleme? I have APFS formatted drive on my MacBook…

The TC is very restricted in terms of protocol. Backup using TM to the TC still uses AFP even for APFS format disks.. the comment about SMB to sharepoint does not apply to TC.

But the problem is common and frequent with High Sierra. As Tesserax has noted in his first post.. we see this problem continually.

Are only backups to Time Capsule problematic (its odd, I was using it for years, once it saved my ***, and was able to install new macOS using it, after my disk broke) or to any network source? I was considering buying a NAS, and using it for TM backups.

No.. TM is lousy to any network target.. although a good NAS is well worth it in the future. Strongly recommend Synology.

But at least a major part of the problem is just Time Machine.

We are recommending to people having issues.. just give TM a rest.. until Apple sorts the problems which they have given no indication of doing to this point. Download and trial Carbon Copy Cloner. It is a lot more reliable.

If you still want to use Time Machine even if just occasionally run it to a local disk plugged into the computer by USB.

If you want to have a go fixing TM.. try doing a reset. This is difficult as Apple did not provision it.. so you need to be a bit hacky to manage it. Instructions here.

Re: Time Capsule backing up one computer but not the other

Sorry, that didn't help. See if any of the following articles can shed some additional light:

• If you can't back up or restore your Mac using Time Machine - Apple Support
• Time Capsule Backup Disk Not Available without restart - ASC
• C19. Backup delayed or The backup disk is not available - Pondini

I do recommend CCC as excellent balance of price, performance and functionality. (no commercial connection). Other backup software is certainly around.. SuperDuper has been popular for many years.. and Chronosync which is rather more complex and expensive.

The advantage of backup to local USB drive is CCC can create a bootable clone. This is a tremendous advantage if things ever go bad. It also means you have a backup that is immediately able to prove itself as valid backup. Just boot from it. Small 2.5" USB drives are now so cheap.. buy one of suitable size and put a label on it.. bootable clone of Macbook xyz.

I do both.. USB clone.. which I keep aside.. renew about once a month or so and backup to network target.. which is easier and stays current.. I do a test backup of TM to an Asus router just to keep my hand in the TM world.. it fails about every 2 months for multiple reasons. I was doing TM to a Synology NAS which was better than the Asus with USB drive. But I am actually trying to find cheaper options for people.. and since Apple is giving up the airport line a router with the ability to TM would be useful.

This issue appears to have started with macOS Sierra and has continued with High Sierra. Primarily it is with Time Machine backups to the Time Capsule as it doesn't seem to affect backups to locally attached drives. Basically, Time Machine has become more and more unreliable when used with this method. A number of us have been recommending users to use Carbon Copy Cloner instead to perform incremental backups to a Time Capsule.

However, if you still wish to pursue using TM with a TC, the following may help:

1. Check your Mac first:

   • Remove or disable any anti-virus programs that it may be running.
   • Verify that it does not have any adware or malware present. I would suggest that you consider using Malwarebytes for Mac if you currently aren't already doing so.
   • Configure your Mac's network configuration to use, as a minimum: IPv6 Link-local only

2. For the Time Capsule (TC):

   Use a fixed local IP address for the TC.

   Use a 16-character or less base station name for the TC. Also do not include special characters or spaces in the name.