Ultra 2: Adding a different drive make to a mirror

Would have been nice to actually see the SMART stats of the drive in question. Generally different vendors have different opinions about when a drive can still be called "healthy" or to be ore precise "fit for the intended purpose". So for example most consider it acceptable that a disk destined for desktop machines shows some relocation errors and even in that case "some" may vary between a dozen and some hundreds, depending on the vendor. Now while this may be fine for desktop usage - and truth be told, the average user really won't notice - the ReadyNAS seems to be a lot more picky there, and for good reason. I came to believe that the ReadyNAS actually expects a flawless disk otherwise it will report it as failed. In turn it's not uncommon for vendor tools to report a disk to be fine all the while it will get rejected by the ReadyNAS over and over again. Some vendors just replace the disk in such a case, others may point out that using a desktop drive in a NAS is not the intended use case and deny replacement.

-Stefan