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Regular Visitor
kubus1
Posts: 3
Registered: ‎02-01-2009
0

New Maxtor STM3500320AS (500GB) S.M.A.R.T. - Problem

Hi!

I have the above drive for 3 months now and didn't use it much because its only for backups. Today I copied data from one partition to another on this drive, and S.M.A.R.T-Values changed like crazy:

 

HD-Tune has about 6 seconds refresh-rate for SMART, and

 

every 6 seconds:  * Seek Error Rate increased +230

every 6 seconds:  * Raw Read Error Rate increased +300.000 (after 250.000.000 switching back to 0)

Hardware ECC Recovered has always the same value as Raw Read Error Rate

 

What does that mean?

 I'm really concerned after a SMART-Tool showed "health-status: bad" when i bought the drive.

btw. its also affected by the firmware-issue...

 

SMART

 

 

 

The disk passed all SeaTools-Tests

 

 

 

Yottabyte
fzabkar
Posts: 4,651
Registered: ‎01-27-2009
0

Re: New Maxtor STM3500320AS (500GB) S.M.A.R.T. - Problem

I believe that the raw 48-bit Seek Error Rate attribute is encoded as follows:

topmost 16 bits = total number of seek errors
bottom 32 bits = total number of seeks

Therefore the Seek Error Rate is equal to ...

(total number of seek errors) / (total number of seeks)

In your case ...

4299089076 = 0x0001003EE4B4

... so your drive has experienced 1 seek error in 4,121,780 (= 0x3EE4B4) seeks.

Seagate drives appear to begin life with an assumed SER of 1 error in 1 million seeks. This equates to a normalised attribute value of 60. If the drive's SER improves, then this value increases, otherwise it falls.

The normalised attribute appears to follow a logarithmic pattern:

90% = < 1 error per 1000 million seeks
80% = < 1 error per 100 million
70% = < 1 error per 10 million
60% = < 1 error per million
50% = 10 errors per million
40% = 100 errors per million
30% = 1000 errors per million

Your current value is 66 which is better than 1 error per million but worse than 1 error per 10 million.

The Raw Read Error Rate appears to reflect a sector count rather than an error rate, although I'm not sure of this as I've yet to see a 48-bit raw value with anything other than 0 in the upper 16 bits.

Anyway here are the results of my investigations:
http://groups.google.com/group/comp.sys.ibm.pc.hardware.storage/msg/030c515959145d44?dmode=source

Based on your results, I expect that the lower 28 bits may reflect a sector count, allowing for 268,435,456 reads. The uppermost bits may hold an error count. The cycle is probably repeated for the next block of 256K reads, and the normalised value is probably incremented or decremented depending on the new error count. However, this is only a guess.

Your current normalised value is 117, which probably suggests that the drive's read performance is improving.

If we use your statistics, then we have 300,000 sectors being read every 6 seconds. This amounts to a transfer rate of 25MB/sec.

Similary, there are 230 seeks every 6 seconds, ie 26ms per seek.

If each seek corresponds to a switch between tracks, then there are approximately 652KB per track, at least in the zone where your testing is being done.
Regular Visitor
kubus1
Posts: 3
Registered: ‎02-01-2009
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Re: New Maxtor STM3500320AS (500GB) S.M.A.R.T. - Problem

Sorry for posting without much a clue of the topic.

It was such a shock for me to see the "error rates" climb so dramatically, so i had to ask whether i have to worry about my data and didnt have the nerves to find it out by myself.

 

Thanks a lot for sharing your knowledge

Kurt

Yottabyte
fzabkar
Posts: 4,651
Registered: ‎01-27-2009
0

Re: New Maxtor STM3500320AS (500GB) S.M.A.R.T. - Problem

Please do not apologise. It is Seagate who should be apologising for withholding information about its SMART attributes.

The "knowledge" that I have accumulated is still only conjecture and hypotheses based on experimental data and research. In fact your information has supplied several important pieces to add to the puzzle.

Please note my frequent use of words such as "probably", "guess", "appear", "suggest", "expect". This should tell you that I'm not 100% sure of anything.

I can already see some errors in my post. For example, instead of saying that "the cycle is probably repeated for the next block of 256K reads", I should have said "256M reads". Also, when I calculated a 25MB/s transfer rate, I should have said that this corresponds to a transfer rate between one partition and another. In fact the data rate across the SATA interface is actually more like 50MB/s since you would be reading from one partition and writing to another. This would also mean that the average number of bytes per track is 1.3MB rather than 650KB.
Regular Visitor
kubus1
Posts: 3
Registered: ‎02-01-2009
0

Re: New Maxtor STM3500320AS (500GB) S.M.A.R.T. - Problem

I knew what you meant. 25Mb/s was exactly the speed of the operation. Looks all very plausible for me.