And the reason why I’m having another go at Restic is that I’ve upgraded the computer and the last data restoration was successfully completed running deja-dup.
So my question was, and remains, what’s stopping Restic
It means that you run a program that computes a checksum (hash) for file(s). Restic stores the files in such a way that the name of the file is the same as the checksum/hash of the contents of the file. E.g. if the checksum/hash for a given file’s contents is “abcd1234”, then restic would save that file with the name “abcd1234”.
The purpose here is that one can later on check if the file has become corrupt by computing the checksum/hash of the file’s contents again - if that checksum/hash matches the name of the file, then the file is fine, but if the checksum/hash of the file’s contents no longer matches the name of the tile, then the file no longer has the same contents in it as it had when it was saved the first time.
Linux, macOS, etc has tools to check various types of checksums/hashes, and one of those types is named “SHA256”, and there are tools for that. On Linux the command for that tool is sha256sum and you run it with the file you want to check as the argument, e.g. sha256sum thefilename. It will then output the SHA256 checksum/hash of that file’s contents, and you can compare it with the name of the file to see if they match or not, as per above.
He was giving you information about how to build the tool named psha. If you want I can build it for you (so you get a single binary that you can run to check the hashes of your entire repository in one go). Do you want that? If yes, let me know what operating system you are on and whether or not it’s 64-bit.
So, to clarify, this is the disk that you backed up your system to before reinstalling it the “first” time (before you started this forum thread), correct?
Did you do this on the backup repository on that disk that you have had problems with since starting this forum thread? I’m not entirely sure why you’d start modifying the repository that we’re trying to debug, hence the question.
Can you elaborate - in what way did you upgrade it? The OS or the hardware? Do you mean that you were able to restore your files from another backup, or where/how does the deja-dup come into the picture?
“Did you do this on the backup repository on that disk that you have had problems with since starting this forum thread? I’m not entirely sure why you’d start modifying the repository that we’re trying to debug, hence the question.”
I still don’t know how I can check that a new external HDD has “problems” - It is the drive that I purchased specifically to hold the restic repository, I agree that it’s possible to have problems even though new and unused by me but since it isn’t demonstrating any read/write inconsistencies, an wild fluctuations of write speeds, any corrupted files copied from it I don’t know if the drive that’s holding the snapshots can be diagnosed as being the source of any problems.
I have removed the screws from the case, removed the actual drive and connected to the motherboard via SATA and power cables.
The host PC RAM has run a memory test for a day and didn’t indicate any issues.
I have upgraded to a Ubuntu 19.10, and Deja-Dup came into the picture because I am unable to have any confidence in Restic, I can make snapshots, I have issues pruning them (I don’t need the data from when I asked here for a tip last September.
I’ll do some more research and try to run sha256 on a file within the repository
and it’s restic from the Snap store - 0.9.6