Did the system ever work as intended? Or did something change to “break” performance? Reimaging the macOS client back to a known good state is another thing to try:
- Using Recovery Mode, reimage the client back to a base install of macOS.
- Reinstall any third-party network drivers.
- Verify the latest driver version and macOS compatibility. Unfortunately, it is common for new versions of macOS to break compatibility.
- Verify speed of Thunderbolt cables and which Thunderbolt ports are in use.
- Thunderbolt 1 and Thunderbolt 2 cables look physically identical but provide different types of performance. Using Thunderbolt 1 cables with Thunderbolt 2 compatible devices will not realize the full performance capabilities of PowerScale or the Apple client.
Thunderbolt speeds can be checked from Apple menu > About this Mac > System Report > Thunderbolt.
- This ATTO technical bulletin shows which Thunderbolt ports to use on various types of Apple hardware to avoid disconnects and performance issues: ATTO Technical Bulletin January 2020.