4 ms·

I had this happening for a while, and I tracked it down to time-machine backups starting. Every hour the backupd cronjob would trigger and I'd get a minute or s

I had this happening for a while, and I tracked it down to time-machine backups starting. Every hour the backupd cronjob would trigger and I'd get a minute or so of beachball. Similar WATCHDOG termination message. It crashed a couple times and corrupted the backup database. I disabled time-machine and haven't had any freezes since.

derefr 6y ago
Is it a remote time-machine backup, i.e. to a Time Capsule (or a NAS pretending to be one)? Time Machine used to use AFP, but since AFP was deprecated, it now exclusively uses SMB for remote backups. (Specifically, it creates a sparsebundle image on the SMB share, and then locally mounts it.) Now, Apple has their own implementation of SMB; and it seems to have been seeing frequent updates in Catalina (see https://support.apple.com/en-ca/HT210803 https://support.apple.com/en-ca/HT210803). Since the Apple SMB stack has some decent amount of kernel integration—and Time Machine doesn’t really have any—I’d guess that recent changes to Apple SMB are also the culprit for any freezes where it’s in the critical path. And Apple SMB seems likely to blame, because there are already other well-known regressions from the recent changes to Apple SMB. Seemingly, there’s a lot of cowboy coding going on in this part of the system right now. For example, macOS can no longer connect to SMB shares via their mDNS names (e.g. smb://example.local). This means that any SMB server that shows up in the Finder sidebar (through an mDNS announcement configured to achieve AFP or Time Machine serving) now just chokes and kills the Finder process when you try to connect to one of its exposed SMB shares through that sidebar connection (see e.g. https://community.synology.com/enu/forum/3/post/129160 https://community.synology.com/enu/forum/3/post/129160). You now have to explicitly connect to the share using its IP (e.g. smb://10.0.0.1) from the Finder ⌘K modal. Weirdly enough, Time Machine itself isn’t broken for the SMB shares it auto-discovers through its configuration modal, so presumably they realized their error in that specific case and made Time Machine pre-resolve the mDNS name in the smb:// URI to an IP address, before attempting the connection. But they forgot to add this same code to the Finder. :/
- riobard 6y ago
  I'm hitting the stupid SMB bug everyday but the symptom seems to be different. I tried to manually connect to `smb://nasbox.local` in Finder and it works with `nasbox.local` appearing in the sidebar. I can also click `nasbox` (without `.local` and this is advertised by the avahi-daemon on the nasbox I believe) and it opens the network shares fine. However, if the Mac goes to sleep for a while and then later wakes up, I can no longer access the shares with the same message "The operation can’t be completed because the original item for “folder_name” can’t be found". This is so damn frustrating.
  - vardump 6y ago
    > This is so damn frustrating. Agreed. And then there's that extremely childish "Windows 95 blue screen" icon representing SMB shares... Really professional.
    - derefr 6y ago
      I think that icon was meant to be bait for Microsoft. The host metadata, as it shows up in the macOS Finder/open dialogs/etc, is configurable by having your host publish an mDNS _device-info._tcp service record. You can publish a display name (as arbitrary unicode), an icon (as a machine model name), etc. I'm guessing Apple figured that if they made the default icon insulting, that might incense Microsoft into building mDNS support into their SMB stack, just in order to use it to broadcast that _device-info service, to make Microsoft SMB present more professionally on macOS clients. Sadly, Microsoft never bothered. But at least I get to use it to make my Linux homeserver look like an Xserve! (See https://www.tumfatig.net/20170607/let-mac-os-auto-discover-your-smb-shares/ https://www.tumfatig.net/20170607/let-mac-os-auto-discover-y...) (Though, sadly, this exact combination of mDNS-announcing-SMB is what is broken in the newest macOS, so I can't recommend you follow the above guide right now. Maybe we'll get support for this back in a few releases...)
      - riobard 6y ago
        To be honest, Xserve is the only sane option for displaying a NAS (with its many drive bays! :)

derefr 6y ago

Is it a remote time-machine backup, i.e. to a Time Capsule (or a NAS pretending to be one)? Time Machine used to use AFP, but since AFP was deprecated, it now exclusively uses SMB for remote backups. (Specifically, it creates a sparsebundle image on the SMB share, and then locally mounts it.) Now, Apple has their own implementation of SMB; and it seems to have been seeing frequent updates in Catalina (see https://support.apple.com/en-ca/HT210803 https://support.apple.com/en-ca/HT210803). Since the Apple SMB stack has some decent amount of kernel integration—and Time Machine doesn’t really have any—I’d guess that recent changes to Apple SMB are also the culprit for any freezes where it’s in the critical path. And Apple SMB seems likely to blame, because there are already other well-known regressions from the recent changes to Apple SMB. Seemingly, there’s a lot of cowboy coding going on in this part of the system right now. For example, macOS can no longer connect to SMB shares via their mDNS names (e.g. smb://example.local). This means that any SMB server that shows up in the Finder sidebar (through an mDNS announcement configured to achieve AFP or Time Machine serving) now just chokes and kills the Finder process when you try to connect to one of its exposed SMB shares through that sidebar connection (see e.g. https://community.synology.com/enu/forum/3/post/129160 https://community.synology.com/enu/forum/3/post/129160). You now have to explicitly connect to the share using its IP (e.g. smb://10.0.0.1) from the Finder ⌘K modal. Weirdly enough, Time Machine itself isn’t broken for the SMB shares it auto-discovers through its configuration modal, so presumably they realized their error in that specific case and made Time Machine pre-resolve the mDNS name in the smb:// URI to an IP address, before attempting the connection. But they forgot to add this same code to the Finder. :/

riobard 6y ago
I'm hitting the stupid SMB bug everyday but the symptom seems to be different. I tried to manually connect to `smb://nasbox.local` in Finder and it works with `nasbox.local` appearing in the sidebar. I can also click `nasbox` (without `.local` and this is advertised by the avahi-daemon on the nasbox I believe) and it opens the network shares fine. However, if the Mac goes to sleep for a while and then later wakes up, I can no longer access the shares with the same message "The operation can’t be completed because the original item for “folder_name” can’t be found". This is so damn frustrating.
- vardump 6y ago
  > This is so damn frustrating. Agreed. And then there's that extremely childish "Windows 95 blue screen" icon representing SMB shares... Really professional.
  - derefr 6y ago
    I think that icon was meant to be bait for Microsoft. The host metadata, as it shows up in the macOS Finder/open dialogs/etc, is configurable by having your host publish an mDNS _device-info._tcp service record. You can publish a display name (as arbitrary unicode), an icon (as a machine model name), etc. I'm guessing Apple figured that if they made the default icon insulting, that might incense Microsoft into building mDNS support into their SMB stack, just in order to use it to broadcast that _device-info service, to make Microsoft SMB present more professionally on macOS clients. Sadly, Microsoft never bothered. But at least I get to use it to make my Linux homeserver look like an Xserve! (See https://www.tumfatig.net/20170607/let-mac-os-auto-discover-your-smb-shares/ https://www.tumfatig.net/20170607/let-mac-os-auto-discover-y...) (Though, sadly, this exact combination of mDNS-announcing-SMB is what is broken in the newest macOS, so I can't recommend you follow the above guide right now. Maybe we'll get support for this back in a few releases...)
    - riobard 6y ago
      To be honest, Xserve is the only sane option for displaying a NAS (with its many drive bays! :)