macOS: External Disk Access before login

Channels DVR Server Troubleshooting
#1

Setup: mac mini, running the latest version of macOS Catalina (10.15.7) and channels 2022.02.03.2057.

I had noticed channels sometimes failing to record as expected due to an inability to stat the directories, etc. I had chalked this up to general weirdness on the system after the upgrade from Mojave, but last night discovered the proximate cause being that macOS was not mounting the external drives until a user had logged in.

Ok, did a little digging and found reference to autodiskmount settings to correct this at this github gist

Made the setting changes this morning, rebooted and saw that channels was able to see the disk in the settings web gui prior to anyone logging in. Success! (I thought) Unfortunately that was short-lived as I saw the Troubleshooting page mark "Disk Write Access" as failed. So while the disks are being mounted, they appear to be read-only until a user logs in.

I'm really trying to avoid setting auto-login, does anyone know how to configure macOS to have write access to these external drives prior to login?

#2

Additional details:

  • SSHing in as user id 501 before login: I can touch files on the external drive while channels-dvr (which is running as user 501) still reports failure in the troubleshooting page.
  • after killing channels-dvr, it is still unable to write to the external drive until the GUI is logged into
#3

Success (for now?) The missing setting was giving channels-dvr full Full Disk Access permission in System Preferences. While I would prefer channels to be able to be restricted to a specific location on disk for reading and writing, I will take this over having to enable automatic login.

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