I'm trying it now, After plugging in I get this message:
"The distk you inserted was not readable by this computer."
Followed by three options:
I try "Initialize..."
The Disk Utility opens.
The disk in question is listed on the disk utility as:
500.11 GB Generic USB Disk Media
-SMART Status is "not supported" (whatever that means)
The disk has 2 "disks" below it, both are light grey, which I take it means something to the tune of "not mountable."
One is called "disk1s1" and contains 497.05 GB. The other is called "Linux Swap." This contains 3.05 GB. Selecting either of this and clicing the "mount" button in the Disk Utility does nothing, they continue to list "Not Mounted" as their "Mount Point."
Is it possible to mount this Linux HD?
This article gives various methods to access Linux filesystems
One thing about the virtual machine approach mentionned in this
article is that you could boot the old Linux OS along side OSX,
if that is of any interest.