Today I disabled mDNS as it was required by one of my services, the only problem is that to do so it forces me to stop my smb share of a time machine backup.
Playing around with the system (with mDNS disabled) I achieved to recreate the share with the same settings and time machine enabled (just required me to restart smb), this is the trick, after importing the share on my mac it actually allowed me to backup on that disk (i’m using a .local dns domain configured on my dns server). I checked on Global “Network” Configuration that mdns was disabled while this worked.
After this when I disable the share it does not allow me to enable it again for the same reason “mDNS is required to enable Time Machine”. Actually this seem not right as of now (maybe it was required previously or it is the .local domain).
I think this might be converted to a simple warning instead of a deny to enable the share.
In adding to this I tried to set the domain as .lan instead of .local and it still worked, so my conclusion is that you just need an hostname. mDNS is not required for time machine
Afaik, you shouldn’t use .local for a local domain because it is reserved for… drum roll… mDNS.
It probably is.
What exactly still worked? Already connected time-machine destination? Mb your DHCP/A record for <truenas>.local still has been cached.
I’m on a 15.7.1 as well, and I cannot add new arbitrary time-machine destination. Seems like it relies on mDNS. Because Mac is for true pros. And true pros never use FQDN (for backups)!
I already replied saying that I updated the local with lan and the result is the same (i know that the local is used for mdns, this is the reason for the updating to .lan).
I successfully updated the time machine with the new domain after mounting the disk (with .lan), i also flushed the cache and completely removed the .local domain from the responsible (local) dns server.
Even that the backup works, so maybe I was thinking that it is not anymore required to use .local.
Completely deleted smb share, backup files and deleted from time machine setting, mounted disk with .lan, selected in time machine and completed backup after this I also verified it.
I’ve tested it myself. I’ve created new (basic time machine) share. Then mounted it via FQDN in finder. Under the time machine setup window there were 2 (new) available shares test-mdns on <truenas-hostname>.local and test-mdns on <fqdn>.
I wasn’t able to disable mDNS because of aforementioned check. So it seems that @Glydric was absolutely right. And I was wrong. And I shouldn’t punch apple.
@awalkerix, it seems that there is a UX bug, and the mDNS strict check (for timecmachine) has to be removed or changed to simple warning.
drum roll… 