Hello William, I believe this has something to do with losing connectivity while your Mac is performing a backup to your NAS. Since your Mac uses disk image files to perform backups over the network, my understanding is that these can become corrupted under certain circumstances. Unfortunately, I don’t think there’s really anything you can do besides recovering any files that you need from the old backup, then allowing Time Machine to proceed and start fresh. As you say, this is the second time it’s happened and I don’t think there’s much you can do to prevent it from happening a third time beyond trying to mitigate how often the connection drops (e.g. try to connect to the internet via ethernet rather than wirelessly). I’d be interested in hearing others’ perspectives on this but according to this support article, Apple puts it right out there that there could be corruption when using a NAS not manufactured by Apple.
Grant > On Nov 26, 2015, at 12:53 PM, William Windels <william.wind...@gmail.com> > wrote: > > Hello all, > > I have a nas from qnap to make time-machine backups and mostly it works fine > But Since I use this nas for Time-machine since january 2015, it’s the second > time, now and one tim > e in july, that all backups from the past are deleted. > > I receive the followingg message: > :application alert system dialog Time Machine completed a verification of > your backups on “BackupSchijf(TimeMachine)”. To improve reliability, Time > Machine must create a new backup for you. Click Start New Backup to create a > new backup. This will remove your existing backup history. This could take > several hours.” > > I found no specific reason of this problem on the internet and also, the > macbook of my wife is also connected to the nas for time-machine and she > makes backups since january without any problem. > > My macbook is running 10.11.1 and my wife runs 10.10.5. > But, since my problem was also there in july , with 10.10.5 I think, it > doesn’t matter which version of osx is installed. > > All idea’s are very welcome. > > Kind regards, > William Windels > > -- > The following information is important for all members of the Mac Visionaries > list. > > If you have any questions or concerns about the running of this list, or if > you feel that a member's post is inappropriate, please contact the owners or > moderators directly rather than posting on the list itself. > > Your Mac Visionaries list moderator is Mark Taylor and your owner is Cara > Quinn - you can reach Cara at caraqu...@caraquinn.com > > The archives for this list can be searched at: > http://www.mail-archive.com/macvisionaries@googlegroups.com/ > --- > You received this message because you are subscribed to the Google Groups > "MacVisionaries" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to macvisionaries+unsubscr...@googlegroups.com. > To post to this group, send email to macvisionaries@googlegroups.com. > Visit this group at http://groups.google.com/group/macvisionaries. > For more options, visit https://groups.google.com/d/optout. -- The following information is important for all members of the Mac Visionaries list. If you have any questions or concerns about the running of this list, or if you feel that a member's post is inappropriate, please contact the owners or moderators directly rather than posting on the list itself. Your Mac Visionaries list moderator is Mark Taylor and your owner is Cara Quinn - you can reach Cara at caraqu...@caraquinn.com The archives for this list can be searched at: http://www.mail-archive.com/macvisionaries@googlegroups.com/ --- You received this message because you are subscribed to the Google Groups "MacVisionaries" group. To unsubscribe from this group and stop receiving emails from it, send an email to macvisionaries+unsubscr...@googlegroups.com. To post to this group, send email to macvisionaries@googlegroups.com. Visit this group at http://groups.google.com/group/macvisionaries. For more options, visit https://groups.google.com/d/optout.
