Recovering library after a HD crash

[Mister Underhill]

Hi! I'm sure I'm not the first person to run into this problem, but I can't seem to find a thread anywhere to help me solve the issue.

Here's the situation:

My hard drive crashed--like, no longer working or accessible. So I am not able to export my library. I was running an older version of Calibre -- 5-something, I think? For one reason or another, I was not up to date.

But, thanks to File History (I'm on PC), I do have a backup of the Calibre Library folder on an external HD.

I've replaced my HD, done a fresh Win11 install, installed the latest Calibre v7.18, and copied the backup library folder back onto the new HD.

My problem is trying to get my library into the new Calibre install. I've tried using "Switch/Create Library" to point to the folder, but it returns an error message that says "There is no existing calibre library at [path]."

Any ideas or suggestions on how to restore my library would be GREATLY appreciated!

[theducks]

metadata.db is what makes it recognized as a 'Calibe Library' (folder)

The folder that contains this is the Library (and the name).
The name can be anything OS legal, but is best if you stay with basic ASCII characters.

I change the name from the default for my working Library (that is the one I back up)

The reason, if your Calibre configuration folder gets damaged, Calibre puts the defaults back and 'Calibre Library' will now show (without your books as that is not the Library you wanted)

Instant warning that something we WRONG and you should start your recovery plan.

[Mister Underhill]

Ah, okay. In the folder there are a bunch of metadata.db files, but they all include a datestamp in the filename. For instance, the latest one is "metadata (2024_09_09 15_59_25 UTC).db".

So should I just rename that to metadata.db?

Also, I notice that there are a bunch of datestamped .json files named "metadata_db_prefs_backup (DATE).json". Are these configuration files?

Thanks so much for the response!

[BetterRed]

Originally Posted by Mister Underhill

Ah, okay. In the folder there are a bunch of metadata.db files, but they all include a datestamp in the filename. For instance, the latest one is "metadata (2024_09_09 15_59_25 UTC).db".

So should I just rename that to metadata.db?

Also, I notice that there are a bunch of datestamped .json files named "metadata_db_prefs_backup (DATE).json". Are these configuration files?

Thanks so much for the response!

Read Post # 9 first

I would try copying "metadata (2024_09_09 15_59_25 UTC).db" to "metadata .db", ditto the "metadata_db_prefs_backup (DATE).json" file. And then try pointing calibre at the library folder.

If that works do a Library check. If that's okay, delete the dated metadata.db and metadata_db_prefs_backup.json files.

Whilst I have File History enabled on my calibre libraries, I regard it as a last resort backup source for an entire library. However, on more than one occasion it has saved me a lot of grief when I've made a mistake when editing a format file… e.g. deleting the substantive content rather the head and tail bumph.

I use a file synchronisation tool (GoodSync) to backup the data I don't want to lose, which includes calibre libraries.

BR

[theducks]

Ouch! That sounds like your backup was on Google drive.

That really messes up Calibre because Calibre uses (##) for the {ID}

GD is not compatible with A calibre Library (see the FAQ) because it changes file names (adds (its own) .

[Sirtel]

Originally Posted by theducks

Ouch! That sounds like your backup was on Google drive.

That really messes up Calibre because Calibre uses (##) for the {ID}

GD is not compatible with A calibre Library (see the FAQ) because it changes file names (adds (its own) .

The OP said the backup was on an external drive.

[theducks]

Originally Posted by Sirtel

The OP said the backup was on an external drive.

Then where did the '( timestamp )' come from?

[Sirtel]

Originally Posted by theducks

Then where did the '( timestamp )' come from?

From File History?

[BetterRed]

@Mister Underhill - I just re-read what you wrote.

If you Restore the library folder from File History it will restore its latest copy of sub-folders and files automatically… i.e. metadata(<most recent date>).db will be restored to metadata.db… etc.

Now I'm wondering of you're proposing to have calibre use the File History copy of the library. IMO that's not a good idea.

BR

Originally Posted by BetterRed

I would try copying "metadata (2024_09_09 15_59_25 UTC).db" to "metadata .db", ditto the "metadata_db_prefs_backup (DATE).json" file. And then try pointing calibre at the library folder.

If that works do a Library check. If that's okay, delete the dated metadata.db and metadata_db_prefs_backup.json files.

Whilst I have File History enabled on my calibre libraries, I regard it as a last resort backup source for an entire library. However, on more than one occasion it has saved me a lot of grief when I've made a mistake when editing a format file… e.g. deleting the substantive content rather the head and tail bumph.

I use a file synchronisation tool (GoodSync) to backup the data I don't want to lose, which includes calibre libraries.

BR

[BetterRed]

Originally Posted by theducks

Then where did the '( timestamp )' come from?

As Sirtel said, from File History:



BR

[theducks]

Originally Posted by BetterRed

As Sirtel said, from File History:

Attachment 210882

BR

I did not even know that existed

[Mister Underhill]

First of all--thanks to everyone for taking the time and for the helpful suggestions!

Originally Posted by BetterRed

Whilst I have File History enabled on my calibre libraries, I regard it as a last resort backup source for an entire library.

Definitely a last resort situation. I'm normally pretty good about having a fairly current backup image of my HD too, but I got sloppy this time.

Anyway, to be clear, I have the File History on a NAS, not Google Drive. I'm still in the process of trying to rebuild this computer and wasn't really ready to do the full restore yet, so I downloaded the Calibre folder from the NAS instead of restoring it through File History. I guess File History is adding the datestamp for new versions of the file? It never occurred to me. The info that File History cleans things up when you restore accounts for my issue, so thanks, BetterRed. I've been lucky enough that File History is a "Break Glass in Case of Emergency" deal that I've only ever had to use to recover the odd file or folder.

Yesterday I tried renaming the most recent .db and .json files, then pointed Calibre at the folder. It worked, mostly, but after reading these posts this morning and doing the Library Check I see that there are some files within the library that also got date stamps added, which is causing a few problems. I'm going to try to restore the folder instead, and I'll report back the results.

Thanks again for all the helpful comments--you have saved me a lot of hair-pulling trying to figure this out.