I was backing up my RAID-5 to a local hard drive with duplicati’s most recent canary. While manually copying my duplicati backup folder to a spare drive, I had a handful of read errors during the hours-long copy to my USB drive. So 3 data files of 500 MB are not copied to the spare drive and are unreadable.
My thought was to just forgo recovering the 3 corrupt files and just rebuild them from the RAID-5 cource, but I don’t know how. The Home screen GUI says that I have 14 versions of the backup.
So here’s what error I got. In Windows 10 doing the copy gave me this error:
Can’t read from the source file or disk.
[I clicked *skip* so I could worry about those files later]
All 3 of my corrupted files are 500 MB dblock files. Two were from last August, one from last month. I would like to re-point duplicati to my new backup file location and give it the command to rebuild, but don’t understand how. My RAID system is degraded but still functioning for now, so I need to ensure the duplicati backup is pristine while I wait for my replacement hard drive.
And maybe I should use smaller dblock files next time. I thought this would increase efficiency of drive usage, but a corrupted file that big (in case something catastrophic happens to the degraded RAID-5 array) would be likely hard to retrieve data from than, say, a 25 or 100 MB file. NTFS and ReFS seem to be so reliable … more corruption seems to be on physical drives than the file system nowadays, especially since UPS systems and modern OSes are able to avoid most hard crashes.