Re: FEATURE Req: integrate badblocks check into fsck.reiser*

[Hans Reiser <reiser@namesys.com>]

Ric Wheeler wrote:
>
>
> David Masover wrote:
>
>> Peter wrote:
>>
>>> On Fri, 01 Sep 2006 17:27:20 -0500, David Masover wrote:
>>> snip...
>>>
>>>>> both mkfs.reiserfs and fsck.reiserfs have -B option to accept list of
>>>>> bad blocks. We thought that should be enough.
>>>>
>>>> It really should.  Why bother with a patch?  Just write a wrapper
>>>> script
>>>> that runs badblocks and passes in the list to mkfs.
>>>
>>>
>>> It was just a thought from userland. My perspective was that a user,
>>> not a
>>> hard-boiled geek, might get lulled into a false sense of security
>>> but may
>>> not have the wherewithal to write a wrapper. If nothing else, when the
>>> final doc is written (did I say final?:)), it should include a notice
>>> about not running badblocks.
>>
>>
>> Well, let's see...  Most hard drives come more thoroughly tested at
>> the factory than anything badblocks would do.  Also, it seems
>> redundant to have every single mkfs have to implement a badblocks flag..
>>
>> I'd suggest a universal wrapper, then, or a modification to the
>> "mkfs" frontend, so that this works the same way across all
>> filesystems. Something like "mkfs -B -t reiser4"
>
>
> I don't think that modern drives that fail writes are worth using for
> a brand new file system.
>
> While failing reads is quite common and can be caused by temporal
> issues (dirt on the platter, a bad write, etc), failed writes are
> almost always a sign that you have a serious issue.  Almost all modern
> drives remap each failed write to a bad sector automatically.  This
> action only fails if you have exhausted this remapping area (or have
> some really nasty issue like a bad cable, bad write head, etc).
>
> Having mkfs ignore bad writes would seem to encourage users to create
> a new file system on a disk that is known to be bad & most likely not
> going to function well.  If a user ever has a golden opportunity to
> toss a drive in the trash, it is when they notice mkfs fails ;-)  This
> option to mkfs sounds like an invitation to disaster.
Yes, you are right, the option should be to run badblocks and then fail
if it finds any.
>
> The other tools (debugreiserfs, reiserfsck, etc) do need to be able to
> handle bad blocks as well as possible since they are often needed
> during a salvage operation. in order to recover data (which might need
> to be migrated to a new disk). It is not clear to me that passing a
> list of bad blocks helps them as much as a robust general purpose
> error recovery support.
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