On Thu, Jan 20, 2011 at 7:10 PM, David C. Rankin
On 01/20/2011 05:38 PM, Istvan Gabor wrote:
First thank you Dave, Pete and John for your help, second I apologize for the late response.
In the meantime I removed the hard disk in question from the system and inserted it into another computer (not as a RAID device, just as a normal SATA disk). In that other system the drive operates with no problem, there are no ticks, copying to the drive goes with up to 40-60 Mbit/sec without hanging, and there are no kernel error messages.
So it is/was either a controller problem, or a driver problem I guess.
Should I try another controller with a different chipset?
I will run smart test later, it's too late now.
Thanks again,
Istvan
Istvan,
I have seen similar behavior with seagate drives in dmraid arrays. I don't have an answer as to why this occurs, but I always felt that it had something to do with problems handling bad-block reallocation while the disks were in arrays. I know that is handled at the drive level and shouldn't matter, but.... I have split arrays into single disks when this occurred, fscked, run bad-blocks and rebuilt the arrays and have had them run for another month or so before the same issues occurred. I still have the same drives running non-raided with no issues at all 2 years later.
Another issue that will cause dmraid to desync is using 'savedefault' in grub to provide failover to another kernel or OS in the event of a failed boot. If you have changed 'default #' to 'default saved' and then added 'savedefault' or 'savedefault #' to your boot entries in grub, get rid of them and go back to 'default #' and see if that doesn't help.
dmraid has been solid for me for at least 8 years, but when this type of issue pops up, you realize how much voodoo it relies on that makes tracking down the exact issue difficult. The dmraid mailing list is 'dm-devel@redhat.com'. The list is low-volume (1-2 posts per day), so it wouldn't hurt to subscribe and run the issue by the devs to see if they may not have a better answer.
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