[smartmontools-support] How to fake an error to test the short/long test detection capability of smartctl?

Gilson Urbano Ferreira Dias gilsonurban at gmail.com
Fri Jul 22 10:19:45 CEST 2022


What about the SCSI standard? WRITE LONG (10)(16) are still valid?

Regards,

Gilson Urbano

On Thu, Jul 21, 2022 at 6:58 PM Franc Zabkar <fzabkar at internode.on.net>
wrote:
>
> I think you will find that READ/WRITE LONG have been retired from the
> ATA standard. In fact, even in those drives that still support these
> commands, the result can be junk data, so it would be inadvisable to use
> them.
>
> See Response #5:
>
> https://www.deepspar.com/blog/Read-Ignoring-ECC.html
>
> Here is a real example:
>
> https://www.recoveryforce.com/spinrite-a-data-recovery-program/
>
> Presumably Spinrite uses the READ LONG command, and this is probably the
> reason that it sometimes returns junk data.
>
> -Franc
>
>
> On 21/07/2022 11:00 pm, Gilson Urbano Ferreira Dias wrote:
> > Franc,
> >
> > Thanks for the useful information.
> >
> > Just for documentation purposes on the mailing list, I figure out that
> > the similar commands for SCSI are WRITE LONG (10) and WRITE LONG (16).
> >
> > https://www.t10.org/ftp/t10/document.05/05-344r0.pdf
> > <https://www.t10.org/ftp/t10/document.05/05-344r0.pdf> (Page 87)
> >
> > https://linux.die.net/man/8/sg_write_long
> > <https://linux.die.net/man/8/sg_write_long>
> >
> > Regards,
> >
> > Gilson Urbano
> >
> > On Wed, Jul 20, 2022 at 9:03 PM Franc Zabkar <fzabkar at internode.on.net
> > <mailto:fzabkar at internode.on.net>> wrote:
> >  >
> >  > The ATA standard provides a Write Uncorrectable Ext command for this
> >  > purpose. A pseudo-uncorrectable sector is created.
> >  >
> >  > --------------------------------------------------
> >  > 7.66.2.2 Pseudo Uncorrectable Logical Sectors
> >  >
> >  > If the FEATURE field (7:0) contains a value of 55h, the WRITE
> >  > UNCORRECTABLE EXT command shall cause the device to indicate a
failure
> >  > when subsequent reads to any of the logical sectors that are
contained
> >  > in the physical block of the specified logical sector are performed.
> >  > These logical sectors are referred to as pseudo uncorrectable logical
> >  > sectors. Whenever a pseudo uncorrectable logical sector is accessed
via
> >  > a read command the device shall perform normal error recovery to the
> >  > fullest extent until:
> >  >
> >  > a) the error recovery process is completed, the UNCORRECTABLE ERROR
bit
> >  > is set to one, and the ERROR bit is set to one; or
> >  >
> >  > b) a command time-out that applies to error recovery control occurs
> >  > before error recovery is completed and an error is reported as a
result
> >  > of the command time-out (see 8.3.3).
> >  >
> >  > As part of reading a pseudo uncorrectable logical sector, the device
> >  > shall perform error logging (e.g., SMART, device statistics) in the
same
> >  > manner as an Uncorrectable error (see 6.3.6).
> >  > --------------------------------------------------
> >  >
> >  > 7.66.2.3 Flagged Uncorrectable Logical Sectors
> >  >
> >  > If the FEATURE field (7:0) contains a value of AAh, the WRITE
> >  > UNCORRECTABLE EXT command shall cause the device to mark the
specified
> >  > logical sectors as flagged uncorrectable. Marking a logical sector as
> >  > flagged uncorrectable shall cause the device to indicate a failure
when
> >  > subsequent reads to the specified logical sector are processed.
> >  >
> >  > As part of reading a flagged uncorrectable logical sector, the device
> >  > should not perform error logging (e.g., SMART, device statistics) in
the
> >  > same manner as an Uncorrectable error (see 6.3.6).
> >  > --------------------------------------------------
> >  >
> >  > On 21/07/2022 12:06 am, Gilson Urbano Ferreira Dias wrote:
> >  > > Hi,
> >  > >
> >  > > I would like to know what is the best/correct approach to
fake/mock an
> >  > > error to test the detection capability of smartctl.
> >  > >
> >  > > Regards,
> >  > >
> >  > > Gilson Urbano
> >  > >
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