My Sandisk G-Drive isn't backing up automatically on MacBook Pro

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My Sandisk G-Drive isn't backing up automatically on MacBook Pro

I've been using a Sandisk g-drive Armor Lock device for backups for several years ard rarely had problems. However, I just returned from a three-week trip during which the drive was not connected to my MacBook. On returning home, I reconnected and unlocked it. After about 18 hours, I decided to make sure it was working correctly and opened the Time Machine settings. It hadn't made a backup since the day I left on my trip and disconnected the external drive. The device is set to back up hourly, so it should have had multiple backups in the time since I had reconnected it to the MacBook and unlocked it. I used the command to make it start a backup, which it did. When I looked again after a bit more than an hour, it had not completed a second backup. What steps do I need to take so that the device will automatically perform backups as scheduled? I haven't tried contacting SanDisk, although I probably will do some troubleshooting research on their site while waiting for replies in this forum.

[Re-Titled by Moderator]

Original Title: sandisk g-drive backups

MacBook Pro 13″, macOS 15.6

Posted on Aug 21, 2025 12:29 PM

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Answer 1

Tesserax

Level 10

157,356 points

Aug 21, 2025 06:21 PM in response to NJM55

It sounds like the issue is less with the G-Drive ArmorLock hardware itself and more with Time Machine not properly resuming its automatic schedule after a long gap. Time Machine can sometimes get "stuck" if it hasn’t been able to run for a while—especially after a drive is locked or disconnected for an extended period. The fact that you can trigger a manual backup tells us the drive is working, but Time Machine’s scheduling service may not be firing off as expected.

See if any of the following can help:

Open System Settings > General > Time Machine. Make sure the drive is still selected as your backup disk, and that “Back Up Automatically” is enabled.
Remove the ArmorLock drive from the Time Machine list, then add it back again. This forces macOS to refresh the scheduling and permissions with that disk.
In System Settings > Battery, confirm that your Mac is allowed to back up while on battery (if that applies to your usage) and that sleep isn’t preventing the backups from running.
After re-adding, leave the drive connected and unlocked, then wait an hour or two. If it still doesn’t auto-run, you can reset the Time Machine scheduler with the following commands in the Terminal. This resets Time Machine’s scheduling without wiping backups.

sudo tmutil disable
sudo tmutil enable

If after this it still won’t auto-trigger, I’d lean toward a macOS scheduling issue rather than the SanDisk drive. In that case, testing with another external drive—even temporarily—can confirm if it’s Time Machine itself. If the other drive backs up hourly, then ArmorLock’s unlock/lock cycle might be interfering, and SanDisk’s support would be worth reaching out to.

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