As with all things LTO, getting your drivers sorted out can be a bit of a hassle. Canister tries to help you as much as possible by detecting any missing drivers when LTO hardware is detected. These drivers are then downloaded to your Downloads folder and opened.

Each LTO machine requires these drivers to function properly:

  • macFUSE

  • LTFS

  • ICU

Canister will also download an installer for Canister's Catalog functionality.

Software Drivers

Which version you require for LTFS and ICU depends on your LTO drive brand. When Canister detects an LTO drive, it offers to download the required drivers for you:

Unfortunately, the LTO powers that be - IBM, HPE, and Quantum - do not properly sign their drivers for macOS. So starting in macOS Catalina, you'll see an alert that everything won't be installed automatically:

If you see this alert, right-click the installer, then click Open. This will allow you to install without triggering the warning. With Big Sur, this workaround became mandatory.

Hardware Drivers

Since Big Sur's release, Apple no longer ships drivers for Host Bus Adapters. HBAs are the intermediate devices between your Thunderbolt device and the LTO SCSI device. Every Thunderbolt LTO drive ships with one:

  • Most brands, including recent mLogic units, use ATTO (Download)

  • MagStor uses Areca

  • Some brands might use SANPoint

If your Mac lists an Ultrium SCSI device on the SAS page of System Information, you're good to go. If not, please contact your LTO manufacturer to get you up and running.

To be 100% sure your ATTO driver is running, try kextstat in

If ATTO isn't listed, you can load the driver manually:sudo kextload /Library/Extensions/ATTOExpressSASHBA4.kext

Apple silicon

To get macFUSE working on M1s, a downgrade of the security settings might be required.

To run an Apple Silicon Mac with reduced security, reboot your Mac. After the chime, press and hold the power button until you see Loading startup options under the Apple logo. Select Options and click Continue. Choose an administrator account and enter its password.

Now go to Utilities > Startup Security Utility and choose Reduced Security. Select both checkboxes underneath and click OK.

Reboot, and go to System Preferences > Security and Privacy > General. Click the Lock icon at the bottom left corner, enter your password, and click Allow in front of the message that says ``System Extension by ATTO and Benjamin Fleischer was blocked.