Re: using dd (or dd_rescue) to salvage array

[Stefan *St0fF* Huebner <st0ff@gmx.net>]

On 07.02.2012 05:24, Keith Keller wrote:
> On Mon, Feb 06, 2012 at 10:37:38PM +0100, Stefan *St0fF* Huebner wrote:
>>  From the logical point of view those lost 8k would create bad data -
>> i.e. a filesystem problem OR simply corrupted data.  That depends on
>> which blocks exactly are bad.  If you were using lvm it could even be
>> worse, like broken metadata.
> FWIW, xfs_repair has spit out over 100k lines on stderr, but when I
> mounted before the repair (this is suggested if you need to replay the
> log), everything seemed intact.  So I'm not yet sure what to make of
> things; perhaps it'll be fine, or perhaps I need to start over.
> (Alternatively, perhaps the next rsnapshot run will expose problems.)
>
>
> On Mon, Feb 06, 2012 at 10:38:27PM -0500, Phil Turmel wrote:
>> But, I reviewed the OEM documentation for the 7K3000 family, and they
>> clearly document support for the SCT ERC commands (para 9.18.1.2).
> If I'm reading the docs right, then the 5K3000 also supports them (if
> you're really cheap and can tolerate the slower speeds).  At this point,
> if we're waiting till April for real ''enterprise'' drives, I can't see
> anything too bad about getting one or two of these and testing them out
> in my environment--the EARS drives are bad enough with my configuration
> that it's hard to imagine being any worse.  (To be fair, I have to blame
> the 3ware 9550 controller a bit too; I have EARS drives on other 3ware
> controllers without all these issues.)
>
> --keith
>
>
>
Sounds promising.  If you're really lucky, the blocks were freed by the 
fs and nothing has gone...

Stefan