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| Thread ID: 115638 | 2011-01-27 19:02:00 | Nuke, Wipe, or Format ? | Strommer (42) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 1173200 | 2011-01-28 06:37:00 | Yup. I would highly recommend running a zero fill wipe. That will write to every sector and if there are some bad, they should get reallocated in the process. |
fred_fish (15241) | ||
| 1173201 | 2011-01-28 07:18:00 | Yeah but if any sectors do get reallocated it means there is physical damage in the drive so it should be replaced anyway. HDAT2 has a full re-zero feature but on a 1TB drive it will take quite a while. |
Agent_24 (57) | ||
| 1173202 | 2011-01-28 07:49:00 | There is ALWAYS some bad sectors on every disc. They SHIP with bad sectors. The drive firmware generally has two defect lists to remap bad sectors, the first is static for defects identified during manufacture and the second is dynamic to cope with wear and damage (I blame cosmic rays :)) over the life of the drive. A continuously growing dynamic reallocated sector count is indeed bad news, but one or two occasionally is quite common, and is why the mechanism is there in the first place. Run a zero fill (followed by a one-fill if you are paranoid, to check for 'stuck bits') and if that completes without errors you should be good to go. You should always have a good backup anyway. Even if your drive has a perfect SMART score, it is still just as likely to fail at any given moment as one with a couple of reallocated sectors. |
fred_fish (15241) | ||
| 1173203 | 2011-01-28 08:37:00 | Most of my drives have 0 reallocated sectors on the G list. I have only one drive which has 2 reallocated sectors and which still works. I had a 80GB Seagate which had 1 reallocated sector and which completely failed one day. The rest have reallocated counts so high and increasing so fast that the drives are useless. My observations match what Google found in their own study: Our results confirm the findings of previous smaller population studies that suggest that some of the SMART parameters are well-correlated with higher failure prob- abilities. We find, for example, that after their first scan error, drives are 39 times more likely to fail within 60 days than drives with no such errors. First errors in re- allocations, offline reallocations, and probational counts are also strongly correlated to higher failure probabil- ities. (labs.google.com) |
Agent_24 (57) | ||
| 1173204 | 2011-01-28 12:39:00 | Interesting paper, although As is common in server-class deployments, the disks were powered on, spinning, and generally in service foressentially all of their recorded life. They were deployed in rack-mounted servers and housed in professionally-managed datacenter facilities This may produce differing results than a typical 'real world' environment, with more chance of vibrations, minor impacts, environmental contaminants etc. and a lot more powering on & off, with the associated thermal and inertial stresses. Therefore random bad sectors are more likely to be a result of external causes, rather than the disk spontaneously wetting it's own pants. :D Also the following from the same text Given the lack of occurrence of predictive SMART signals on a large fraction of failed drives, it is un- likely that an accurate predictive failure model can be built based on these signals alone. and Our results are surprising, if not somewhat disappointing. Out of all failed drives, over 56% of them have no count in any of the four strong SMART signals, namely scan errors, reallocation count, offline reallocation, and probational count. In other words, models based only on those signals can never predict more than half of the failed drives. But I certainly haven't seen as many disks as they have :lol: so I can't dispute their data. All I'm saying is that I have seen many disks with some reallocated sectors that truck on successfully for years, with the number in the SMART table the only symptom. Also it occurs to me that, if dynamically reallocating sectors did not appreciably reduce drive failures, they wouldn't bother building it into the drives. I imagine margins are pretty tight in HDD manufacture. :p |
fred_fish (15241) | ||
| 1173205 | 2011-01-30 06:20:00 | wiping disk is more assured | cucorney (16197) | ||
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