Two external SATA HDs eject when used simultaneously via FW800

[Doc69]

When I connect a bare SATA drive to my 2010 Mac Pro 5,1 via a Seagate GoFlex FW800 adapter, then it works fine. But when I connect two of them simultaneously, then they both eject and are nowhere to be found in Disk Utility. After that, I can't make any of them mount individually again (or even show up in Disk Utility) until after I reboot.

The Seagate GoFlex FW800 adapters also have a USB 2.0 port, and if I connect one drive via FW800, and the other via USB 2.0, then they both mount simultaneously. But if I use the FW800 ports on both adapters, then they both eject and disappear.

Does anyone know what's going on and how to solve this?

 

[Doc69]

I was told that because I use two identical Seagate GoFlex adapters with bare drives, they both get the same ID (hard coded in the adapter) and therefore conflict. So the only solution is to get another hard drive dock and use that with one of the Seagate adapters. I'm buying the OWC Voyager Q.

 

[Gav Mack]

I was told that because I use two identical Seagate GoFlex adapters with bare drives, they both get the same ID (hard coded in the adapter) and therefore conflict. So the only solution is to get another hard drive dock and use that with one of the Seagate adapters. I'm buying the OWC Voyager Q.

Is the right answer. The device ID is different for the 3.5 and 2.5 adapters though so you can mix a pair of them ok.

 

[Doc69]

Is the right answer. The device ID is different for the 3.5 and 2.5 adapters though so you can mix a pair of them ok.

Do you know why I only get the conflict when I use two bare drives with two Seagate adapters over FW800, but not when one of them is connected to the USB 2.0 port? Also, I don't get a conflict when using two of Seagate's own GoFlex or Backup Plus drives with the FW800 adapters.

 

[Gav Mack]

Do you know why I only get the conflict when I use two bare drives with two Seagate adapters over FW800, but not when one of them is connected to the USB 2.0 port? Also, I don't get a conflict when using two of Seagate's own GoFlex or Backup Plus drives with the FW800 adapters.

It's a problem with the 2.5 fw adapter I've found and it's a right PITA. I use them for quick connecting all sorts of bare drives but thankfully I also have a usb 3.0 version too.