Time Machine must create a new backup for you?

I just bought a My Cloud to make a Time Machine backup because my usb ports are no longer mounting my WD passport external HD.  I want to take in my Macbook Pro (running Yosemite 10.10.3) to Apple to repair it but I wanted to make a backup first just in case they delete my data.  My last one was 200 days ago.  So I spent 4 days creating a new time machine backup on My Cloud.  Then a day later I got a message saying something to effect that “Time Machine completed a verification of your backups… Time Machine must create a new backup for you.”  The saved sparsebundles changed to .purgeable and it seems I lost my backup.  So I was forced to manually delete my old backup and I am now in the slow process of creating another backup.  

I guess my questions are does this happen often with Time Machine backups on the My Cloud?  Is there any way to fix this without deleting my entire backup?  What is the cause?  Did certain files somehow get corrupted?  My concern is that I really want to take my computer in soon to Apple to get it repaired because my Applecare warranty expires next month but I am paranoid about losing data when I give it to them.  I want the peace of mind of having a current backup but so far I was forced to delete my very first backup on My Cloud.  Not very reassuring.  I should note that before my issues with my usb ports, my time machine backups on ext HDs have never had this problem (been backing up to ext HDs for around 5 yrs).  

You can try to fix this problem (and therefore avoid creating the new backup) by following the instructions here:


Thanks dario.  I already deleted the old time machine backup and in the process of creating a new one.  I’ll try the fix recommended in the article you linked if it happens again.  

hi surf1der - can I tell you how lucky you are that you caught this in time? 

I bought the mycloud exactly for the same purpose - I needed to bring my mac air in for service and wanted to make sure everything was backed up properly with time machine prior to service

the genius bar wiped out and restored my computer and told me to Not restore from back up but to only manually drag files over as I needed them from the back up and then see if after two weeks my problems were resolved. 

well… after two weeks I realize that time machine or mycloud has wiped out all of the back ups from prior to the restoration and they are gone. i think i am getting the same message about creating a new back up every time it wants to back up but i didn’t notice it until now… and then it says “this will remove your existing back up history”…I thought the whole point of time machine was for this to not happen!? even at the genius bar today they said nothing should be deleted unless you manually overwrite.

has this happened to anyone else? is there any way to recover my lost back up once this has happend? 

ok – i can see in other forums now that this is not a unique problem and I see that there is a way to prevent it from happening. but since it’s already happened to me, if anyone can help me to restore the lost back ups I’d be really grateful. Are they still on the harddrive somewhere or are they gone?