Yeah, this is logic that scsi couldn't do by itself, but md can, since it can recover the data. Also, wouldn't we want to check (and even set) the auto-reallocation (AWRE/ARRE) mode page bits on the drive when md loads, to let the disk do as much as it can with remapping? Or does that belong outside of md? Andy There are limited spare resources in a drive, which are wasted if consumed by "normal" transient errors. It's much better to recover/rewrite the sector inside md, and if persistant then spare the sector at the drive level. At Fortune Systems (largest M68K Unix mfgr in early 1980's) we tried auto sparing on first error and it completely drove us crazy when the errors were introduced by poor power and EMI coupling. The drives that were returned, were almost always good, it was the system environment that triggered the majority of the errors. I've been running software raid here on a large FC array ... and a number of relatively normal errors have repeatedly taken the raid array off-line and potentially exposed the data to corruption since the only recover is to "mkraid -R" and accept the data state as it is. John - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
