Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 14 Jun 2019 12:25:25 +0200
From:      peter.blok@bsd4all.org
To:        "Kenneth D. Merry" <ken@kdm.org>
Cc:        freebsd-scsi@freebsd.org
Subject:   Re: Bad SSD drive - what happens with unreadable data
Message-ID:  <C0246C62-8B27-4A96-821F-07F1EEADBE34@bsd4all.org>
In-Reply-To: <20190613133439.GE66314@mithlond.kdm.org>
References:  <C13683A4-B5CB-43B9-84EC-1E18BD88D63E@bsd4all.org> <20190613133439.GE66314@mithlond.kdm.org>

next in thread | previous in thread | raw e-mail | index | archive | help
Hi Ken,

Yes I already had changed the time-outs and retries. I ended up using =
ddrescue out of the ports collection. Despite the amount of read errors =
I was able to recover the important stuff.

SSD drive is going back under warranty (hopefully). It is less than a =
year old and hardly used.

Peter

> On 13 Jun 2019, at 15:34, Kenneth D. Merry <ken@kdm.org> wrote:
>=20
> On Thu, Jun 13, 2019 at 13:02:48 +0200, peter.blok@bsd4all.org wrote:
>> Hi,
>>=20
>> I have a bad SSD drive. If I read it with dd and conv=3Dnoerror, what =
happens with the unreadable areas? Does it fill with zeroes, or does the =
driver still copy what it was able to read?
>>=20
>> I???m getting ATA status 51 back, many blocks in a row. Followed by =
chunks of readable data, followed by unreadable data.
>>=20
>> Is there a modepage or something else to tell the drive to pass on =
the bad data?
>>=20
>> Any other ideas?
>=20
> You might try the recoverdisk(1) utility.  It is designed for that =
sort of
> situation.
>=20
> One of the recommendations in the recoverdisk(1) man page is to lower =
the
> retry count for the disk driver you're using, so you don't wind up =
retrying
> a lot in situations where the drive itself has tried and failed to =
read the
> data.
>=20
> In looking at the source, it appears tht it will only write out the =
blocks
> it is able to read successfully.  IMO, it would be good to have at =
least an
> option to write zeros in output file in the areas where the reads =
failed.
>=20
> Ken
> --=20
> Kenneth Merry
> ken@kdm.org




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?C0246C62-8B27-4A96-821F-07F1EEADBE34>