Time Machine: Multiple machines disturb each other

[dkrizic]

Hi,

I have a QNAP TS-219 running Version 4.12 (newest). I have two Macs:

• Mac mini
• MacBook Air

Both run Yosemite 10.10.2. Both do a Time Machine backup to QNAP which works fine, as long as only ONE machine uses the TMBackup share, no matter which one. As soon as the other did a backup, both complain with the error message, that it has to recreate the whole backup (sorry, I am not at home, so I don't see the actual message). This is very annoying and renders Time Machine useless. This used to work before. I have no clue, what the reason is.

What can be the reason?

Regards,

Darko

[MarkNF6X]

This is a shot in the dark by a brand new QNAP user, but do your two Macs have different names? If they are both named the same, then maybe they're both trying to write into the same directory, thus overwriting each other's backups.

[sodium]

this is a known problem -- that is why I moved my TImeMachine backups to a TimeCapsule.
The TimeCapsule does a nifty trick, when the second machine tries to allocate the backup disk, it gets an error that the backup disk is not available...

[anentropic]

sodium do you have any reference for the known problem? can it really occur just sharing a disk even if writing to separate files?

any further info much appreciated, I am trying to troubleshoot similar problem with my Drobo 5N, though I think I encountered it with only a single machine connected (as TM is usually turned off on the second laptop)

[sodium]

I've searched my notes and looked in my browsers but I must have deleted the bookmarks to the information
multiple hosts writing information to a nas works fine -- it only breaks the timemachine backups

sorry I can not help further