Basically, is there a way to force the refresh of the magnetic state of data? I assume scrub does this only when a read error has been encountered. Does anyone think it would be a good option to write 100% of the data back on request?
I am asking because I have ddrescue running on a hard drive that had data written to it years ago and the data was never even looked at. Then, some blocks started to go bad so I started the recovery and wow, is it going slow. It does have some read errors, some pending sectors, and some multizone error rate, whatever that is, but they are not increasing at a steady rate, it will go a few days without them increasing. I suspect this is merely some stale data that could have been prevented by something like dd if=dev of=dev once a year. Anyway some performance numbers, obviously not related to Btrfs: I started this Nov 22nd with about 1 day of downtime. $ ddrescue -n -a 10000 /dev/sdi4 opt.img opt.log GNU ddrescue 1.16 Press Ctrl-C to interrupt Initial status (read from logfile) rescued: 44177 MB, errsize: 9879 kB, errors: 207 Current status rescued: 55578 MB, errsize: 9879 kB, current rate: 30 B/s ipos: 58881 MB, errors: 207, average rate: 131 kB/s opos: 58881 MB, time since last successful read: 0 s Copying non-tried blocks... === START OF READ SMART DATA SECTION === SMART Attributes Data Structure revision number: 16 Vendor Specific SMART Attributes with Thresholds: ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x000f 196 196 051 Pre-fail Always - 269625 3 Spin_Up_Time 0x0003 177 174 021 Pre-fail Always - 6125 4 Start_Stop_Count 0x0032 100 100 000 Old_age Always - 586 5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always - 0 7 Seek_Error_Rate 0x000e 200 200 051 Old_age Always - 0 9 Power_On_Hours 0x0032 083 083 000 Old_age Always - 12753 10 Spin_Retry_Count 0x0012 100 100 051 Old_age Always - 0 11 Calibration_Retry_Count 0x0012 100 100 051 Old_age Always - 0 12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 485 192 Power-Off_Retract_Count 0x0032 200 200 000 Old_age Always - 197 193 Load_Cycle_Count 0x0032 200 200 000 Old_age Always - 588 194 Temperature_Celsius 0x0022 115 085 000 Old_age Always - 35 196 Reallocated_Event_Count 0x0032 200 200 000 Old_age Always - 0 197 Current_Pending_Sector 0x0012 183 183 000 Old_age Always - 1439 198 Offline_Uncorrectable 0x0010 200 200 000 Old_age Offline - 11 199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age Always - 232 200 Multi_Zone_Error_Rate 0x0008 001 001 051 Old_age Offline FAILING_NOW 27189 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
