Re: Feature request: Remove the badblocks list

[Roy Sigurd Karlsbakk <roy@karlsbakk.net>]

>> I'd better want md to stop fixing "somebody else's problem", that is, the disk,
>> and rather just do its job. As for the case, I have tried to manually read
>> those sectors named in the badblocks list and they all work. All of them. But
>> then, there's no fixing, since they are proclaimed dead. So are their siblings'
>> sectors with the same number, regardless of status.
> Just because you can read them, doesn't mean you can write them.
> Clearly, at some point in time, one of your drives failed. You now need
> to recover from that failed drive in the most sensible way.
>> If a drive has multiple issues with bad sector, kick it out. It doesn't have
>> anything to do in the RAID anymore
> 
> And if a group of 100 sectors are bad on drive 1, and 100 different
> sectors on drive 2, you want to kick both drives out, and destroy all
> your data until you can create a new array and restore from backup?
> 
> OR, just mark those parts of all disks faulty, and at some point in the
> future, you replace the disks, and then find a way to tell MD that the
> sectors are working now (and preferably, re-test them before marking
> them as OK)?
> 
> BTW, I just found this:
> 
> https://raid.wiki.kernel.org/index.php/The_Badblocks_controversy

I linked to that earlier in the thread

> Which suggests that there is indeed a bug which should be hunted and
> fixed, and that actually the BBL isn't populated via failed writes, it
> is populated by failed reads while doing a replace/add, AND the failed
> read is from the source drive AND the parity/mirror drives.

It is neither hunted down nor fixed. It's the same thing and it has stayed the same for these years.

> Either way, perhaps what is needed (if you are interested) is a
> repeatable test scenario causing the problem, which could then be used
> to identify and fix the bug.

I have tried several things and all show the same. I just don't know how to tell md "this drive's sector X is bad, so flag it so".

Again, this is not the way to walk around a problem. What this does is just hiding real problems and let them grow in generations instead of just flagging a bad drive as bad, since that's the originating problem here.

Vennlig hilsen

roy
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Roy Sigurd Karlsbakk
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