On 12/04/17 09:51 AM, Greg Freemyer wrote:

Sorry,

But smartctl is the best tool out there and it will only report issues detected in the normal course of use.

You need to access every sector if you want to know if the media is starting to fail. I would:

smartctl --all > pre-scan.out dd if=/dev/sda of=/dev/null bs=10M conv=noerror smartctl --all > post-scan.out

I take it that the "-all" is purely reporting, does not alter the disk in any way?

Then compare your pre- and post- results to see if any serious concerns were found.

Concerns would include correctable media errors, etc. Not just total failures.

ACK. IIR there's a limit to correctable errors in the size of the "look-aside" table and allocated reserved sectors. Or is it tracks?

As to speed, if you can get 4GB/minute read speeds, you can read a TB in about 4 hours.

I get as fast as 8GB/minute on 3 1/2 inch 7200 RPM modern large desktop drives. So that's a TB of reads in 2 hours.

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On 2017-04-14 15:52, Dave Plater wrote:

On 12/04/2017 15:28, Anton Aylward wrote:

...

'smartctl -h /dev/sda' just says "PASSED" which is nice but not detailed. 'smartctl --all /dev/sda' tells me a lot but doesn't seem to tell me what I'm looking for. smartctl -t long /dev/sdX is the command that tests all sectors, if it reports an error send it back. I've successfully extended the life of drives with uncorrectable sectors by using the hdparm --write-sector command on the sector output in smartctl -l selftest.

How do you get the list of bad sectors from smartctl? -- Cheers / Saludos, Carlos E. R. (from 42.2 x86_64 "Malachite" at Telcontar)

On Fri, Apr 14, 2017 at 11:15 AM, Dave Plater wrote:

using "smartctl -l selftest" it gives you the first failed sector. It's a long process if you have many bad sectors. In my case I only had four that I suspect came from a defective sata cable. You don't get a list.

?? How does a bad cable cause a bad sector? The drive electronics themselves take 512 bytes (or whatever the sector size is) of data and generate an appropriate header/footer incuding the ECC info. A correctable read error means the data was only slightly corrupt and the ECC data allowed the data to be corrected. A bad sector means the contents of the sector are corrupted such that the ECC info isn't sufficient to correct the sector data. The sata cable is not involved in the ECC generation process, nor the low level read/verify process. Greg -- Greg Freemyer -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

On Sun, Apr 16, 2017 at 4:54 AM, Dave Plater wrote:

On 14/04/2017 17:33, Greg Freemyer wrote:

...

On Fri, Apr 14, 2017 at 11:15 AM, Dave Plater wrote:

...

using "smartctl -l selftest" it gives you the first failed sector. It's a long process if you have many bad sectors. In my case I only had four that I suspect came from a defective sata cable. You don't get a list.

?? How does a bad cable cause a bad sector?

The drive electronics themselves take 512 bytes (or whatever the sector size is) of data and generate an appropriate header/footer incuding the ECC info.

A correctable read error means the data was only slightly corrupt and the ECC data allowed the data to be corrected.

A bad sector means the contents of the sector are corrupted such that the ECC info isn't sufficient to correct the sector data.

The sata cable is not involved in the ECC generation process, nor the low level read/verify process.

Greg

-- Greg Freemyer

Correction, it was the 5V pin on the connector to the sata power cable that was loose. The sata cable was also defective. Dave P

Thanks Dave, A bad power cable could definitely cause corrupted sectors. I was thinking of the data cable. Greg -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org