Hi GNU ddrescue, I would like to make a suggestion to add another option of sector (hardware block) size of output device and differentiate it from already existing --sector-size for input device - e.g.: --sector-size-in=bytes --sector-size-out=bytes
The problem i encountered is the following: I was restoring from old USB disk /dev/sdb (3TB, logical sector size 4096) to new USB disk /dev/sdc (4TB, logical sector size 512): Disk /dev/sdb: 2.7 TiB, 3000558944256 bytes, 732558336 sectors Units: sectors of 1 * 4096 = 4096 bytes Sector size (logical/physical): 4096 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: dos Disk identifier: 0x000246c6 Device Boot Start End Sectors Size Id Type /dev/sdb1 256 732558335 732558080 2.7T 7 HPFS/NTFS/exFAT Disk /dev/sdc: 3.7 TiB, 4000752599040 bytes, 7813969920 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: dos Disk identifier: 0x000246c6 I omitted --sector-size as it defaults to 512 thinking it matches the /dev/sdc sector size. I did run the following two commands, which took two days: sudo ddrescue -n /dev/sdb /dev/sdc --force rescue.map GNU ddrescue 1.25 Press Ctrl-C to interrupt ipos: 584810 MB, non-trimmed: 0 B, current rate: 15018 B/s opos: 584810 MB, non-scraped: 1764 kB, average rate: 23639 kB/s non-tried: 0 B, bad-sector: 25600 B, error rate: 170 B/s rescued: 3000 GB, bad areas: 50, run time: 1d 11h 15m pct rescued: 99.99%, read errors: 103, remaining time: 3m time since last successful read: 0s Finished sudo ddrescue -r3 /dev/sdb /dev/sdc --force rescue.map GNU ddrescue 1.25 Press Ctrl-C to interrupt Initial status (read from mapfile) rescued: 3000 GB, tried: 1789 kB, bad-sector: 25600 B, bad areas: 50 Current status ipos: 584810 MB, non-trimmed: 0 B, current rate: 0 B/s opos: 584810 MB, non-scraped: 0 B, average rate: 0 B/s non-tried: 0 B, bad-sector: 1781 kB, error rate: 256 B/s rescued: 3000 GB, bad areas: 27, run time: 9h 31m 57s pct rescued: 99.99%, read errors: 13870, remaining time: n/a time since last successful read: 7h 14m 34s Finished However even though ddrescue reported it rescued 3TB, I only ended up with partition that is reported 8x times smaller (4096/512=8): Disk /dev/sdc: 3.7 TiB, 4000752599040 bytes, 7813969920 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: dos Disk identifier: 0x000246c6 Device Boot Start End Sectors Size Id Type /dev/sdc1 256 732558335 732558080 349.3G 7 HPFS/NTFS/exFAT Question1: Is there any way to fix that now without running it again? I'm afraid the disk will not handle another ~48hrs run. Question2: How do you currently specify destination sector size? It does not seem to be possible - no mentioning of that in your manual. Many thanks for your great work, -- LUCIAN MALY, RHCA SENIOR CONSULTANT, CUSTOMER SOLUTIONS GROUP Red Hat Asia-Pacific Pty Ltd | people.redhat.com/lmaly