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Quoting Gordon Henderson <gordon+dcglug@xxxxxxxxxx>:
After a day of massaging, badblocks scans, noodling, fiddling and so on, it's in a stable condition. I was able to deliberately fail the raid arrays on partitions where one side was OK and the other side faulty, and re-build the faulty sides - it's a "trick" I've done in the past to force a re-write of a bad sector with good results, (until such times as I've been able to change the drives), and now all partitions and mirrors read with no bad sectors. (Although all arrays are checked automatically every week anyway using the mdadm tools and this has never flagged an error)
That's a good trick.
So what changed... Well, yesterday afternoon, this popped up:kernel: ata2: limiting SATA link speed to 1.5 Gbpsand after that, everything seemed to just settle down... So they're SATA II drives (3Gb/sec), it's a SATA II motherboard and I used the SATA cables that came with the mobo.
So you'd expect it to be fine then, or at least I would.
So stuff going through my mind right now is a lot of "what if's"... What if the cables were cheap ones only good for 1.5Gb/sec. What if a cable has worked loose? (I drove that box to the co-lo myself and always check connectors before turning on the mains), what if it's just been some cosmic ray, what if I'm just unlucky, what if it's a kernel bug in the SATA driver? (Kernel 2.6.29.3 and I'm now scanning teh changelogs), Who knows.
Could it be a case of a dodgy motherboard, or just plain bad luck?
So I'm now revising my plans - I need to get a new server up there by the end of Feb, but I'm not going to make a mad dash up there now (Sheffield) - I'll build and test this new server, then when I go up, take new SATA cables, and new drives and give it a good testing while I'm up there installing the new server.
That's good then, I guess that is one of the pitfalls of hosting in Sheffield, the long distance to travel, but I guess things like this are a fairly rare occurence?
One thing I have noticed - there seems to be a lack of places openly advertising SATA II cables, but I admit I'm not real expert in that area - is there a big difference between SATA I and II (other than the speed, and I can see why you'd need better cables for 3GB/sec). Maplin seems to be the best place with a range of cables. Aria (who I usually buy from only has 1 SATA II cable (in 2 lengths) and they have right angled connectors which I'm not a fan of when disks are stacked one above the other (even with a gap, the cables still sometimes interfere)
I had a look at eBuyer.com and came up with this... Startech latching SATA cable: http://www.ebuyer.com/product/141695 According to the specs it is SATA 150/300.It seems a lot of cables now seem to be going right angled for some reason. Must be the 'in thing'.
Not sure how good the latching is, I guess it might make it a bit more secure. Other than that I guess getting a hot glue gun to it would fix it in, although saying that, I'd have thought the connector would be secure enough not to come out, but hey, maybe it has done that?
If I see any when I'm browsing I'll let you know, although I was pretty certain at least on SATA/SATA2 that the cables are all now pretty much SATA2. Can't say about SATA3 as I haven't had the chance to check out any SATA3 drives or controllers yet.
Rob -- The Mailing List for the Devon & Cornwall LUG http://mailman.dclug.org.uk/listinfo/list FAQ: http://www.dcglug.org.uk/linux_adm/list-faq.html