Installing ATTO SAS or FC interfaces

These ATTO interfaces add SAS or FC ports to the Mac enabling control of a LTO tape drive or library


The H680 is a PCIe card with dual connectors, each connector supports four SAS drives. There are newer 12Gb cards, but LTO SAS is 6Gb so the H680 is perfect. The H680 support TLR which is needed for LTO-7 and LTO-8.
There are other models that can be used, like the H644 which has one external connector and one internal connector.
With a regular SFF-8088 cable you can connect one LTO drive to each connector.
There are also one to four fan-out SF-8088 cables, with these each connector can support four LTO drives.
If the drive has a Fibre Channel connection then there is an ATTO PCIe FC card.
Note that the ATTO multipath driver does not support tape drives.
Download and install the latest Mac driver and card firmware from the ATTO website.
The PCIe card can go inside the older MacPro or in a Thunderbolt expansion like the Sonnet Echo Express SEL shown here.
YoYotta can supply the H680 + Sonnet. Contact for details.

There are also RAID cards like the R680 or R644 and the ThunderLink SH 2068. 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 the older MacPro, then select PCI from the left hand Hardware list. The ATTO H680 should be listed.

Check for Thunderbolt devices

If using an ATTO card in an expansion chassis, then click Thunderbolt. Here the Sonnet Echo Express Pro is connected to the Mac.

ATTO Driver missing or blocked

Now select SAS or Fibre Channel from the Hardware list. Here the driver has not been installed so no devices are shown. On High Sierra the driver may also be blocked, see the next section.

If missing then download and install the Mac driver for the H680 from the ATTO website

High Sierra System Security

The first time after you install ATTO drivers on a new High Sierra system, you will need to approve the new System Software. Also new installs of system software from YoYotta, 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 and click Allow to enable the System software to load.

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.
YoYottaID LTFS will now be able to control this drive.
The System Information page does not refresh automatically. Click File, Refresh Information or cmd R to refresh the hardware listing.

LTO library connected

Here an HPE MSL4048 with three LTO drives is connected. SCSI Target Device @ 0 has two logical units. The first is an LTO-5 drive, the second is the library robot. If two logical units are not shown then the configuration of the tape library needs to be set to allow external control. The setting for the control path are normally in the partition settings for the library.
SCSI Target Devices 1 and 2 are LTO-5 and LTO-4 drives.

YoYottaID Automation will now be able to control this library.

Adjust link speed for R680 and SH2068

The ATTO SH2068 TB-SAS adaptor and the R680 or R644 PCIe RAID SAS card do not support TLR, so there will be read issues when controlling LTO-6, LTO-7 and LTO-8 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.
The H680 SAS card is not affected.
To reduce the errors, set the PHY link speed to 3Gb/s rather than Auto or 6Gb/s. This is a temporary workaround until you replace the units with an ATTO H680.
With the SH2068 use the Jan 2016 firmware, file name is osx_fls_tlsashbab_160129.dmg, do NOT use the newer Jan 2017 firmware.

To do this open the terminal app and type this to display the current R680 settings.
/Applications/ATTO/ExpressSASRAID2/atsasnvr -p

Or type this to display the current ThunderLink settings.
/Applications/ATTO/ThunderLinkSASHBA/atsasnvr -p

Then type one of the following to change the link speed.
/Applications/ATTO/ExpressSASRAID2/atsasnvr -k 3
/Applications/ATTO/ThunderLinkSASHBA/atsasnvr -k 3

Power cycle the ATTO and restart the Mac.
Then type the first command again to check the new settings they will show PHY Speed: 3 Gb/s

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