Greetings RAIDers, Apologies if this topic has been thrashed here before. Google is not showing me much love on the topic and that which I have found does not convey consensus. So I am coming to the experts to get the verdict. Recent event: I spent a fair amount of time on the line with Seagate support yesterday who informed me that their desktop drives will not work in a RAID array. Now I may have been living in a cave for the past 20 years, but I always had a modem. As I started to dig into this a bit more looking for info on TLER, ERC, etc. from my understanding, these "RAID class" drives simply don't have the same level of error correction as the "desktop" alternative and instead report back to the RAID controller immediately instead of dawdling with fixing the problem themselves. If this is true, then I can understand where this might cause a RAID system some problems. However, I do not understand why the RAID system cannot detect the type of drive it is dealing with and either disable the behavior on the drive or allow more time for the drive to respond before kicking it out of the array. Just to give some background on how I got to this point, but not to distract from the main question, here is where I have been... Over past 5 years, have been struggling with a 4 drive mdraid array configured for RAID5. This is not a busy system by any stretch. Just a media server for my own personal use. Started out using the SATA headers on the MB. Gave up and bought a cheapy hardware RAID controller. Thought better of that decision and went back to software RAID using the hardware RAID controller as a SATA expansion card. Gave up on that and went back to the SATA headers on the MB (had replaced the MB along the way). Over that period, threw out original 4 drives and replaced them with newer bigger Seagate Barracudas. Bought snazzier and snazzier cables along the way. Discovered a firmware upgrade for the Barracudas that I thought had recently fixed the problem. After speaking with Seagate yesterday, I booted off of the SeaTools image and ran tests on all drives. The two suspect drives did have errors that were corrected by the test software. But alas, attempting to reassemble this array fails, dropping one drive to failed spare status and another to spare which has been the behavior I have been fighting for years. So the question becomes, do I try it again with the replacement drives that Seagate is sending me, or do I hang them in my "desktop" and spend the money for RAID Class drives? (I've grown tired of this learning experience and would like to just have a dependable storage system) And to tag onto that question, is there any reason why mdraid cannot detect these "lesser" drives and behave differently? Why would these drives be developing errors as a result of their tortuous experience in a RAID array? Thanks for any light you can shed on this issue. -Randy -- 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
