It's certainly possible that the error I was receiving was a different reason, though similar symptoms. We started seeing filesystems go read-only, and only rebooting would clear it up.
I use that setting on the "Host OS" for VMWare to prevent a whole vm from getting killed.
That setting will maintain a minimum amount of free memory available to prevent a large program that requests memory quick from depleting all available memory and causing the program killer from killing the highest RAM process.
If you are on a Host OS box, the biggest Memory processes are your VMs, and getting one killed off because memory reaches zero is not good.
I don't have any idea how it would fix journal errors on a drive, but I guess it could.
It's been a few years since I put in the tuning, but here's some info that might be useful:
http://communities.vmware.com/thread/20690?start=0&tstart=0
In particular, others had reported seeing this error:
"kernel: journal_get_undo_access: No memory for committed data".
I don't recall that error in my case, but might explain why the tuning fixed the problem. There's a bugzilla for this: