Which OS does Canister support?

Canister requires macOS 10.11 or newer.

Where can I download legacy versions?

Version 20.1 is available for download here and receives continued support until Dec 31th 2020.

Canister is stuck on "Looking for LTO drive"

If you're using a Thunderbolt LTO drive like an mTape, macOS doesn't always register the LTO drive inside your device mTape properly. Check your System Information: there should be an entry on the Thunderbolt page, but also an Ultrium entry on the SCSI or SAS page. If the latter is missing, power cycle the Thunderbolt device and the LTO drive. Sometimes a full Mac reboot is needed.

For macOS Big Sur Users

Big Sur doesn't ship with an ATTO driver, which is required for an mTape. You can download it directly here:


How can I switch between XXH and MD5?

Most of the industry has moved to using XXH (or xxHash64BE, to be exact) but some legacy flows require MD5. Canister used XXH by default. Switching Canister to use MD5 instead will have a serious speed impact on transfers, and no benefits. Only do so when you require MD5 for an existing workflow.

To switch to MD5, open Terminal, paste the following command and hit Return:

defaults write nl.syncfactory.Canister.Mac SFLDefaultsChecksumType -string md5

To switch back, using the following command:

defaults write nl.syncfactory.Canister.Mac SFLDefaultsChecksumType -string xxhash64

Does Canister use LTFS to manage tape backups? What's the difference between using LTFS and TAR in the Terminal?

Canister uses LTFS. The difference between TAR and LTFS is that LTFS is a file system. That means your OS already has the tools included to work with LTFS, which means no vendor lock-in for you. With TAR, you're always relying on a vendor's app to work. With LTFS, that will never happen.

Is it possible to add multiple folders in one transfer?

This is currently unsupported because LTFS introduces fragmentation when transferring multiple folders. Mechanisms to prevent this and allow transfers from folders on the same volume are in active development.

Is it possible to skip or disable verification?

You can safely skip verification by clicking the [X] next to a transfer when the copy part finishes.

A setting to disable verification is coming in a future release.