Warning: WD drives and G5 Incompatibility
 

After weeks of troubleshooting some very strange and specific issues with regard to throughput and the ability for programs like Disk Warrior and iDefrag not being able to work on my external SCSI array, there appears to be a little known but documented bug in the communication between WD drives and G5's.

A quote from the Coriolis site (makers of iDefrag) explains a bit of what is happening:

"Q: Are there any known problems with iDefrag?

A: It isn't a problem with iDefrag itself, but we are currently investigating an apparent compatibility problem between some G5 machines and Western Digital hard disks. It seems that sustained read/write access can sometimes cause the machine's disk subsystem or the disk itself to stop responding. Replacing the disk with a unit from a different manufacturer seems to cure the problem.

We are currently in contact with both Apple and Western Digital regarding this issue."

I'll be replacing my WD drives with the new Seagate 7200.10 500GB drives for testing purposes. If changing manufacturers clears the issues I'm having then the above mentioned bug and it's "fix" is good knowledge.

For now, if you're planning on buying drives either for mass storage, RAID configurations or single-drive internal usage my advice is to stick with the drives that currently do not have any strange bugs. Those would be either the Hitachi or Seagate lineup. I can't speak to Maxtor's reliability since I've never owned any.

I'll keep the forum posted on updates.

Problem solved
 

Further testing showed it wasn't an issue with either the disk utilities or the WD drives, but instead the on-board SCSI controller, which uses a non-standard format in creating the RAID array which, prevents things like Disk Warrior from properly seeing the data.

At this time, I have no data that suggests that the WD5000YS drives are not stable or reliable in an array of any kind. In fact, they're now in an e-SATA PM setup and are running 100% reliable 24/7.

I've had nothing but bad luck with maxtor's, from purchase to RA's on the dead drives. Maybe they are better since the buyout, but I would stick to seagate.