2 Time Capsules (at home/at work) double backup

Yes.. it will work OK.. although you might occasionally get an error pop up when you are home for a few days that it cannot find the work TC.

When you are at work simply configure the macbook to backup to the TC there.. you will be asked if this new backup location is to replace the existing one or use both.. just say to use both.

I want you to check if you can actually mount the disk in Finder.

OSS status 12 is a network problem.. so I want to see if once mounted and available in Finder it doesn't become accessible in TM preferences as well.

By any chance do you have the same name on the TC at work and at home.. that would really mess things up!!

Otherwise I have to admit some confusion as to why this would happen.

You need to give me more details. A screenshot from airport utility of the TC setup at home and at work would be a big help.

Also what OS is the computer running?

If you are running Sierra or High Sierra.. sadly issues with Time Machine are common. It is simply unreliable.

Would you be prepared to use a different backup software at home or work..

We actually recommend this to people now. I use carbon copy cloner .. but there are others like super duper you might already have.

Can you see the TC in airport utility?

If so can you mount the TC hard disk in Finder?

Once mounted in Finder.. try again to select it in Time Machine preferences.

When you setup the work backup did it ask you if you wished to use both backups or to change to new backup and forget the old one? Which did you choose?

Sorry.. but I really need the details I asked for in the previous post.

Just as coincidence .. my Time Machine kicked up a warning when I turned on my computer this morning.. This is only a test setup and I not surprised by the failure.. however to actually forget the username or password is ridiculous.

And using backup to two targets does make it harder to find out what is going on.. again I am testing at the moment to both a local target which I usually have turned off as well as the network. Once the network target has an issue you may need to force it to start again. ie delete the target and reconfigure it.

Time Machine is not very smart and will say it is going to do a new backup.. but will find the old backup and continue.. hopefully. Some more details of this in reference below.

I just tried it on my problem disk above. It has lost the password from keychain.

So I deleted it in Time Machine then immediately selected it again.

Said to keep using both disks.

Not being very smart it then says it is going to do a first backup.

Once it starts it should then discover the backup and continue.

In my case it has failed totally.

What this means is that the backup is no longer valid and you really either verify it and it gets repaired.. (unlikely to work).. or delete the backup and start over. I have done this a few times already in the last couple of months. As I said Time Machine is just not reliable.

Here is console messages.

Starting automatic backup

Attempting to soft mount network destination URL: afp://ray-local@RT-AC3200-82F0._afpovertcp._tcp.local./Backups.backupdb

Mounted network destination at mount point: /Volumes/Backups.backupdb using URL: afp://ray-local@RT-AC3200-82F0._afpovertcp._tcp.local./Backups.backupdb

Checking for runtime corruption on /dev/disk1s2

Disk image /Volumes/Backups.backupdb/z87proimac.sparsebundle mounted at: /Volumes/Time Machine Backups

Network destination already mounted at: /Volumes/Backups.backupdb

statfs call failed, error: 2 No such file or directory

Backup failed because the network destination disk was ejected or disconnected unexpectedly!

Backup failed with error 26: The connection to the server was interrupted.

Starting automatic backup

Destination hgst1 could not be found (url: (null) destinationID: F56155A9-B987-4976-9BBF-5BD4CF962AFE)

Backup failed with error 18: The backup disk could not be found.

Error -35 while resolving alias to backup target

You might also consider doing a Time Machine reset.

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

Particularly on Sierra onwards you must have no anti-virus or extra security software or adware on the computer.

Also if the computer does not directly connect to the TC you will have issues.

Console messages with search backup might tell you more about the problem.