Connecting an mTape or mRack LTO unit

The mLogic mTape and mRack have built in Thunderbolt 3 ports allowing direct connection to a Mac.
The mRack supports one or two LTO drives in a 1U rack height.
YoYotta LTFS together with two LTO drives will write an archive to two tapes in parallel.


The Mac needs software drivers for the ATTO SAS card that is inside the mTape unit otherwise the LTO drives will not be seen.

Install drivers

First check how to Install macFuse on the Mac.

Then download and install the latest ATTO H608 SAS card driver.
The latest mTape units use the ATTO H1208GT SAS card driver.

Connect a thunderbolt cable from the Mac to the LTO drive. Power on and then wait a few minutes for the drive to boot up. There is an LED display on the drive that will cycle through a boot sequence. Open the YoYotta app. Now click the LTFS button on the toolbar of YoYotta. This will check and prompt to download all the LTFS frameworks needed.
Wait until the message Update completed OK appears.
YoYotta LTFS will now be able to control this drive.
Check the Support page to watch a video showing LTFS archiving along with links to all the help topics.

If the LTO drive does not appear, then then you may have an older mTape unit that did not use an ATTO SAS card. Instead you may have an Areca SAS card. These cards are not recommended especially with LTO-7 as you may get read errors.
Here is a link to the Areca SAS card drivers.

If still no luck follow the instructions below to check the hardware.


Checking hardware devices

To check that the Mac can see the LTO drive hold the alt key on the Mac keyboard, click the Apple Menu and select System Information...


Check for Thunderbolt devices

If an mTape device is not shown then try reconnecting the cable and power cycling the unit.
If there is a mTape Thunderbolt interface, then the next step is checking for the internal SAS tape drive.


Check for SAS devices

Make sure the mTape drive is connected and powered on, now a SCSI Target Device @ 0 will be visible. This is the SAS tape drive that is inside the mTape.
If the SAS device is missing, please install the ATTO H608 driver as described below.

Older mTape units used a different internal SAS card. Here is an driver that may work with Intel Macs. So they may not work with Apple Silicon Macs.

After rebooting if there is still no SAS drive visible then contact support at mLogic for assistance.

Note that the System Information page does not refresh automatically. Click File, Refresh Information or Command + R to refresh the hardware listing.


ATTO SAS install

Keep the SAS card inside the mTape updated.
  • Download the macOS Config Tool, macOS driver and macOS Flash Bundle from ATTO SAS downloads
  • There is a ATTO video here showing the ATTO firmware update
  • Install the Config Tool and the macOS driver
  • Allow the driver in Apple System Security as described below
  • Run the ATTO Config Tool
  • Check the card Flash firmware date and update to 2018 or newer
  • In Advanced Settings - Maximum I/O Transfer Size set to Default
  • Reboot the drive and Mac


Allow system software in System Security

When drivers are installed on a new system, you will need to approve the new System Software. New installs of system software from YoYotta, ATTO, OSXFUSE (developer is Benjamin Fleischer) and other drivers may need approval.
You will see a message like this saying System Extension Blocked
Open the Security & Privacy page in Apple System Preferences, unlock the padlock and click Allow to enable the System software to load.

You must click the Allow button locally on the Mac, clicking using remote screen sharing will not work.
If the Allow button is not shown then reboot your Mac, try again to use an LTFS or TAR tape (which will fail) and then check the Security & Privacy page again.
Also ensure that you have the latest macOS 10.13.6, 10.14.6, 10.15.7, 11.6.5 or latest Monterey


Files and Folders access

When running YoYotta with newer macOS versions you may see requests to allow access to folders like Documents, Removable Volumes or Network Volumes. Please allow these requests.
Also you can enable access in Files and Folders in the Security tab as shown in the screenshot.
YoYotta does not need Full Disk Access.


Open YoYotta

In the log there will a message showing that the drive has been detected. The SAS card driver version, firmware level and PCIe speed will be shown.


Open LTFS panel

Now click the LTFS button on the toolbar of YoYotta. This will check and prompt to download the LTFS frameworks needed. Wait until this completes, then open the panel again.
YoYotta LTFS will now be able to control this drive.

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