Re: clearing blocks wrongfully marked as bad if --update=no-bbl can't be used?

[Marc MERLIN <marc@merlins.org>]

On Sun, Oct 30, 2016 at 10:12:34AM -0700, Marc MERLIN wrote:
> Hi Neil,
> 
> Could you offer any guidance here? Is there somethign else I can do to clear
> those fake bad blocks (the underlying disks are fine, I scanned them)
> without rebuilding the array?

On Sun, Oct 30, 2016 at 06:02:42PM +0100, Andreas Klauer wrote:
> > There should be some --update=no-bbl --force if the admin knows the bad
> > block list is wrong and due to IO issues not related to the drive.
> 
> Good point. And hey, there it is.
> 
> mdadm.c
> 
> |                       	if (strcmp(c.update, "bbl") == 0)
> |                               	continue;
> |                       	if (strcmp(c.update, "no-bbl") == 0)
> |                                continue;
> |                       	if (strcmp(c.update, "force-no-bbl") == 0)
> |                               	continue;
> 
> force-no-bbl. It's in mdadm v3.4, not sure about older ones.

Oh, very nice, thank you. It's not in the man page, but it works:

myth:~# mdadm --assemble --update=force-no-bbl /dev/md5
mdadm: /dev/md5 has been started with 5 drives.
myth:~# 
myth:~# mdadm --examine-badblocks /dev/sd[defgh]1
No bad-blocks list configured on /dev/sdd1
No bad-blocks list configured on /dev/sde1
No bad-blocks list configured on /dev/sdf1
No bad-blocks list configured on /dev/sdg1
No bad-blocks list configured on /dev/sdh1

Now I'll make sure to turn off this feature on all my other arrays
in case it got turned on without my asking for it.

Thanks,
Marc
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