On 5/22/2011 6:44 PM, Brad Campbell wrote: > He used WD commodity drives on a "hardware" RAID enclosure that needed > TLER. The RAID-5 kicked out 4 drives in a short period of time, so he > power cycled it and re-initialised the array and it came up fine, but > blank (as it would as he re-initialised it). It was/is an Excel Meridian Data SecurStor Astra ES with 4 expansion chassis. Low end, many would call it junk (myself included). Excel Meridian Data, formerly known as Excel CD-ROM, has been re-badging cheap Taiwanese, and now Chinese, junk since their inception in 1992. Eli stated this gear was sold to UCSC as a packaged, warrantied, storage system, by an unnamed local SoCal vendor. I took the man at his word. We can speculate that he lied about it and tossed it together himself form a catalog, which seems plausible given EMD's business model, but that makes no material difference in this discussion, which is that WD Green drives are not appropriate for RAID arrays, regardless of who selected the components and whose hands assembled the hardware. > Sorry Stan, that's not a failure of the drives. He lost the data due to > limitations in his RAID configuration and bad management. On the contrary. It *is* a failure of the drives. They failed to perform properly in the chosen application environment, because the vendor/end user put them in an unsupported environment. That's the whole theme of this thread, and precisely why I encouraged people to read about this fiasco and the potential costs of using these drives in RAIDs. Whether the spindles motors quit, the PCBs failed, or they were merely kicked offline due to any of a half dozen reasons, these are all drive failures. When a drive goes offline doe you call it "success"? No. What's the opposite of success? Failure. The Astra ES is almost certainly running embedded Linux + md RAID due to its price point. I can't locate the EMD website nor the PDF for this Astra unit because every Excel Meridian domain Google'ing returned is currently squatted. They may have gone belly up. If indeed that box uses embedded Linux + md RAID, TLER wouldn't have been the problem. Multiple drives definitely went offline, but I doubt it's due to a real RAID ASIC with custom firmware and a TLER issue. More likely, given the price, it was a backplane signal quality problem, for which cheap backplanes are notorious. Either way, cheap not-fit-for-RAID drives were stuffed into a cheap RAID box and disaster was the result. People buying these drives for array use aren't dropping them into quality backplanes, but cheap ones. The entire ecosystem of components used to build a WD Green drive array are typically of much lower quality than the drives themselves. Cheap backplane + cheap drives + cheap HBAs = high probability of disaster. In summary, very few people are going to successfully build reliable arrays from these drives. I've seen too many horror stories, the UCSC fiasco being the most severe. I'm simply trying want to prevent others from suffering similar disasters. I think that's a worthy cause. WDC itself says not to use the Green drives in RAID arrays. I'm supplying examples of real world disasters to support WDC's disclaimer, and prevent some heartache. -- Stan -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
