Mounting an ext3/4 Linux external hard drive to OS X
Solution 1:
You can mount ext2/3/4-Volumes using MacFUSE with the fuse-ext2 Driver.
Solution 2:
There's a commercial product from Paragon called ExtFS for Mac.
I did test is for a few days a while back and it wasn't very fast but got the job (of reading my external ext3 drive) done.
You can try-before-buy, so you'll know if that's what you are looking for.
Btw: I do have Linux in a VM on my Mac to access these files and I'll copy the files I need from the Linux VM via SSH to my mac. Or the other option I use enabling a Windows share on the Mac and copy the files from the Linux VM to the Mac using that share.
These files are on an external USB drive, so if your drives are internal you may consider buying a USB docking stating for SATA drive, e.g Sharkoon Quickport Combo. USB drives shouldn't be a problem to connect to a VM - unless as previously mentioned the discs where used in a RAID or with a volume manager like LVM.