On Sat, 2014-06-07 at 18:52 -0600, Chris Murphy wrote: > I wrote: > > How can there still be pending bad sectors, and yet no error and LBA reported? > > So I started another -t long test. And it comes up with an LBA not previously reported. > > # 1 Extended offline Completed: read failure 60% 1214 430234064 > > # dd if=/dev/zero of=/dev/sda seek=430234064 count=8 > dd: writing to ‘/dev/sda’: Input/output error > 1+0 records in > 0+0 records out > 0 bytes (0 B) copied, 3.63342 s, 0.0 kB/s > > On this sector the technique fails. > > # dd if=/dev/zero of=/dev/sda seek=430234064 count=8 oflag=direct > 8+0 records in > 8+0 records out > 4096 bytes (4.1 kB) copied, 3.73824 s, 1.1 kB/s I may be missing something here, but surely after all this faffing about and errors isn't it about time to replicate the data to a new drive and then hit this one repeatedly with a very large hammer. The law of diminishing returns must surely be coming into play by now. > > This technique works. > > However, this seems like a contradiction. A complete -t long results in: > > # 1 Extended offline Completed without error 00% 1219 - > > and yet > > 197 Current_Pending_Sector 0x0022 100 100 000 Old_age Always - 16 > > How are there 16 pending sectors, with no errors found during the extended offline test? In order to fix this without SMART reporting the affected LBAs, I'd have to write to every sector on the drive. This seems like bad design or implementation. > > Chris Murphy-- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
