ATTO SAS interfaces
LTO-1 to LTO-8 drives use 6Gb SAS interfaces, LTO-9 uses a 12Gb SAS interface. However with the correct cable any of these cards can be used for multiple tape drives as the maximum data rate for LTO-5 to LTO-9 of 140MB/s to 450MB/s is still less than 6Gb/s.
ATTO SAS RAID cards like the R680 are not supported, see the bottom of this page for more information.
ATTO H680
The H680 is a PCIe 2.0 card with dual external connectors, each connector supports four SAS drives. The H680 supports TLR which is needed for LTO-7 onwards.
All other H6XX models can be used, like the H644 which has one external connector and one internal connector. Also the H608 which can be used with internal LTO drives.
With a regular SFF-8088 cable you can connect one LTO drive to each connector.
There are also 1 x SFF-8088 to 4 x SFF-8088 fan out cables, with these each connector can support four LTO drives. (No drop in performance).
Put the card in a Thunderbolt expansion like the Sonnet Echo Express SEL shown here.
Note that with the correct cables the ATTO H6XX cards could control eight LTO drives, however the PCIe bandwidth will not be enough to keep them all running at full speed. So you may need two SAS interfaces or update to the H1280GT.
YoYotta v4 subscriptions can be configured for between one and eight LTO drives.
The ATTO H680 is a great card and it is still fully supported by all macOS versions including Sequoia, however it has been replaced by the H1280GT, so it might not be available.
ATTO H1280 + H1280 GT
The H1280 is a PCIe 3.0 card with TLR support and two 12Gb SAS connectors, it has been replaced by the H1280GT.
The H1280 GT model is a PCIe 4.0 card with TLR support and two 12Gb SAS connectors.
All other H12XX models can be used, like the H1244 which has one external connector and one internal connector. Also the H1208 which can be used with internal LTO drives.
Each 12Gb connector has four SAS ports, so with a fan-out cable each connector supports four LTO drives.
The higher speed of 12Gb/s isn't required for LTO drives, but it is fully compatible.
Desktop and most library LTO drives connect using SFF-8088 connectors.
For these you can get 1 x SFF-8644 to either 1 x SFF-8088 or 4 x SFF-8088 fan-out cable.
The LTO drives in some libraries like the Quantum i3 and i6 connect using SFF-8644 connectors.
For these you can get 1 x SFF-8644 to either 1 x SFF-8644 or 4 x SFF-8644 fan-out cable.
With the correct cables the ATTO H1280GT card can control up to eight LTO drives.
YoYotta v4 subscriptions can be configured for between one and eight LTO drives.
ATTO SH 3128
The ThunderLink SH 3128 is a Thunderbolt 3 adaptor that supports TLR and has two 12Gb connectors. These connectors connect to drives using SFF-8644 to SFF-8088 or SFF-8644 cables and work the same way as described above for the H1280GT.
The ATTO Thunderlink SH1068, SH2068 SAS interfaces are not recommended. See the section below about unsupported interfaces.
ATTO SAS install
Keep the card updated. To update ATTO firmware use an Intel Mac.- Download the macOS Config Tool, macOS driver and macOS Flash Bundle from the ATTO website
- There is a ATTO video here showing the ATTO firmware update
- Click for ATTO H6XX SAS downloads
- Click for ATTO H12XX SAS downloads
- Click for ATTO H12XX GT SAS downloads
- Click for ATTO SH 3128 SAS downloads
- 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 if needed
- In Advanced Settings - Maximum I/O Transfer Size set to 1MB
- Reboot the drive and Mac
The Sonnet Echo Express SEL is a compact Thunderbolt enclosure that holds a PCIe card like the ATTO H680. A lot of our customers use this to connect to a desktop SAS LTO drive or tape library. Get the Thunderbolt 3 unit as this means that there is plenty of bandwidth for multiple LTO drives and also daisy chaining other Thunderbolt units. The Apple TB3 -> TB2 adaptor allows connection to older Thunderbolt 2 Macs. There are also other units that hold more than one card.
ATTO ThunderLink SH1068, SH2068 TB-SAS, ThunderStream SC3808, SC4808 adaptors, R680 or R644 PCIe RAID SAS cards do not support TLR which is a required protocol. So they are not compatible with LTFS running on any operating system.
These interfaces are not compatible with tape drives as they do not support TLR protocol. As a temporary workaround when using with LTO tape drives with these interfaces the link speed should be set to 3Gb/s. However there may still be errors. See section at bottom of this page.
Checking hardware devices
To check that the Mac can see the ATTO and LTO hardware hold the alt key on the Mac keyboard, click the Apple Menu and select System Information...
Check for PCI devices
If using an ATTO card inside a Thunderbolt chassis, then select PCI from the left hand Hardware list. The ATTO SAS card should be shown.
Check for Thunderbolt devices
If using an ATTO card in an expansion chassis, or you have a Thunderbolt LTO drive, then click Thunderbolt. Here the Sonnet Echo Express Pro is connected to the Mac. If there is no Thunderbolt device, then try reconnecting or using a different Thunderbolt cable. Also power cycle the Mac, interface and drive.
ATTO Driver missing or blocked
Now select SAS from the Hardware list. Here the driver has not been installed so no devices are shown. On newer macOS versions the driver may also be blocked, see the next section.
If missing then download and install the Mac driver (See ATTO SAS install above for links) Then reboot the Mac.
Note that Thunderbolt drives have a SAS tape drive and SAS interface inside, so they will need a SAS driver from ATTO or Areca. Contact your hardware supplier to find out what driver is needed for the SAS card is fitted to your LTO drive.
Allow system software in System Security
The first time after you install ATTO drivers on a new system, you will need to approve the new System Software. New installs of system software from YoYotta, ATTO, macFUSE (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 Settings or 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 tape (which will fail) and then check the Security & Privacy page again.
Also ensure that you have the latest updates to your version of macOS
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.
ATTO Driver installed
Now the driver is installed and the ATTO ExpressSAS device is shown. No tape drives are connected.
LTO drive connected
Make sure an LTO drive is connected and powered on, now a SCSI Target
Device @ 0 is shown. Here an IBM LTO-5 drive is connected.
YoYotta will now be able to control this drive.
The System Information page does not refresh automatically. Click File,
Refresh Information or Command + R to refresh the hardware listing.
LTO library connected
Here an HPE MSL4048 with three LTO drives is connected.
SCSI Target Device 1 has two logical units. The first is an LTO-5 drive, the second is the library robot.
SCSI Target Devices 2 and 3 are LTO-5 and LTO-4 drives.
If all the SCSI Targets just have one logical unit then the configuration of the tape library needs to be set to allow external control. Check the settings for the control path, which are normally in the partition settings, using the library web browser interface.
For a Quantum i3/i6 library check the Partition Control Path in the web interface and set the Control Interface to Drive. (This defaults to None)
Then refresh the System Information panel and check that one of the targets now shows two logical units.
The YoYotta Library option will now be able to control this library.
SAS troubleshooting
If jobs stop with errors like these, first check that the path in the error includes LTFS. If it does not then you need to check the source or destination drive, NAS or SAN.Problem writing file 'Socket is not connected' (57)
Problem writing file 'Input/output error' (5)
These errors are low level issues sent from macOS that do not give much more information other than writing to the tape has failed.
This could be a SAS/FC interface, LTO drive or tape issue, to troubleshoot follow these steps.
- Eject all tapes
- Download the macOS Config Tool, driver and Flash Bundle from the ATTO website
- Install the Config Tool and the macOS driver
- Run the ATTO Config Tool, check and update the card firmware
- Reboot the drive and Mac
- Run test archive jobs from a local SSD to a new tape
Also save a copy of the YoYotta log + debug as described here
Then send both logs to support@yoyotta.com and we will help you troubleshoot the issue.
LTO drives and SAS interface TLR support
There is a SCSI protocol in the T10 SAS Protocol Layer (SPL-4) called TLR that is required for IBM tape drives.
Note that all LTO-7/8/9 drives are manufactured by IBM.
With LTO-7/8/9 the drive will use TLR because of the higher transfer speeds.
With LTO-6 the drive may use TLR for large file transfers.
If the SAS interface does not support TLR, then you will get read errors that are not signalled.
These errors would remain undetected unless the app used compares the data read back against a checksum of the written data.
HPE, IBM, Quantum, Tandberg and YoYotta only recommend SAS interfaces with TLR support.
mLogic mTape drives use an ATTO SAS controller with TLR support, however some older units did not. If there is a Highpoint or Areca controller this should be updated.
If you have verification issues with an mTape then save and send us a system report from the Apple System Information app and we can advise you as to the type of SAS interface that you have.
If the interface does not support TLR then we recommend installing an ATTO H608, H644, H1208 or H1244 card.
You can find more information on mTape units here, this link also shows how to access the Apple System Information pages.
For the Mac the ATTO H6xx and H12xx PCIe cards support TLR, so these are the only interfaces we recommend.
To use the ATTO PCIe card with a Thunderbolt Mac put it into a Sonnet or other TB PCIe chassis.
H644 and H608 cards can also be used, but ensure they have the correct SAS connectors for your drive.
See this link for more details on the ATTO.
ATTO Thunderlink SH1068, SH2068 TB-SAS, ThunderStream SC3808, SC4808 adaptors, R680 or R644 PCIe RAID SAS cards do not support TLR which is a required protocol. So they are not compatible with LTFS running on any operating system.
If you already have an ATTO R680 or Thunderlink then you will definitely need to replace the unit as soon as possible. An H680 or H1280 can be used instead of the R680 card.
Highpoint RocketStor and RocketRAID devices are not compatible with LTFS + LTO drives.
The Highpoint 6328L is a SATA protocol interface. It has Mini-SAS connectors, but does not support SAS protocol. So this does not work with any SAS RAID or tape devices.
The Highpoint 6328 is a SAS protocol interface. But it does not support TLR protocol, so it cannot be used with LTO + LTFS.
We do not know of any fix for the HighPoint 6328, so this is not suitable for use with LTO-7, LTO-8 and LTFS.
Unsupported ATTO SAS interfaces
ATTO Thunderlink SH1068, SH2068 TB-SAS, ThunderStream SC3808, SC4808 adaptors and the ATTO R680 or R644 PCIe RAID SAS cards do not support TLR, so there will be issues when controlling LTO-6 and newer generation tape drives.
These interfaces are not supported as they do not work with LTFS.
Files are written correctly, but when read back there are undetected soft errors. So the errors would be missed if the copy was not verified. If you get any verification issues, then check these settings.