Re: Scsi errors with Megaraid 300-8x

Justin Piszcz
2006-08-23T15:45:52Z

On Wed, 23 Aug 2006, Johan Groth wrote:

> Mark Lord wrote:
>> Johan Groth wrote:
>
> [snip]
>
>> Basically, given an I/O request for 200 sectors, with a bad sector
>> in the middle at number 100, what SCSI will often do is fail sectors
>> number 1 through 100, one at a time, retrying the entire remainder of
>> the request after each attempt. This takes hours, and results in no
>> data for the first 99 good sectors.
>
> So what you are saying is that after the move to a new box and a new mobo a
> sector has gone bad on that raid slice? Weird, as I was very careful this
> those drives when I moved them.
>
> I mean, the raid controller is the same, the cpus are the same, just more of
> them, the pci-x bus the same so I didn't expect any problems at all.
>
> I was also under the impression that SATA raid controllers work like SCSI
> raid controllers in the way that if a bad sector is encountered the
> controller moves what it can and the mark the sector as bad. I might be very
> wrong about that, though.
>
> However, if I have a bad sector I would like to have that one marked as bad
> so the kernel never tries to read it again. Any suggestions how I do that. I
> assume I have to boot something like Knoppix as sda is my system disk.
>
> Regards,
> Johan
>
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Run badblocks in r+w mode on the bad disk and it will force the disk to
re-allocate the bad sector if it can.

Justin.