Backup program with encryption and selective restore, corrupt resistant

Whatlogin

Estimable
Apr 13, 2014
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Hi,

TL:DR
A solution that create multipart backup archive, but consider each archive as separate (not 001,002,004).


Maybe you can help me. I am planning to make a backup of approx 500GB among many different type of files. I would like to have it encrypted and divided to parts, and then keep it on disk on sync folder (for example Dropbox folder). Then perhaps remove the folder and cloud sync.

Looks easy but I noticed that to pick any file from backup I would need to download whole archive and decrypt it. Another thing that worries me is that if any part of the archive is corrupted then all backup is lost.

So far I thought of:
- just syncing files to dropbox folder and use +boxcryptor (then on any other computer as long as I have boxcryptor with proper key I can even download single file to decrypt it). On cons side, I would be uploading a lot of small files.
- using backup software with e.g. 7-zip compression/ecnryption with encrypt single file option. Same cons - many small files.

Solution would be a program that for example takes 4GB of data, create archive then takes another 4GB and creates new archive. I bad scenario I lose 4GB rather than 500GB. It may be not too perfect with large files, but I do not mind.

Just remembered, I think there was an option in one burning software to span files, span disks? But that exclude automated backup.

Or maybe I should not worry that much :) ?

Or maybe you have some other idea?

Regards
 

USAFRet

Splendid
Moderator
Breaking it into 4GB chunks is non optimal, for a couple of reasons.

1. How do you know what 4GB chunk the file you're looking for is in?
2. What is in Chunk A may depend on files that exist in Chunk B. A won't work without B.
3. 500GB split into 125 chunks of 4GB each is still 500GB.
4. If you locally edit a file that lives in Chunk #83, how is your backup procedure supposed to know this and redo that specific part? What if by editing that file, you now cause Chunk #83 to be larger than 4GB?

What are you actually trying to achieve? A cloud backup?
 

Whatlogin

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Apr 13, 2014
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Thanks USAFRet,

Well ok, I need to make sure on what I want to achieve, that's for sure :)

Looking at my files, I see that 95% is rather one time backup operation. So I think I could mix two.

So if it is one time operation, full backup, then it is not so stupid I guess.

Example:
I took Cobian Backup and make test backup with compression, encryption and split. Looks ok to me. But.....if I loose backup.005 file, I loose all backup (or need to repair).

Checked Comodo, then it is the same, but with cbu files, which is even worse. On their forum there are plenty support requests about unrecoverable backup.

As for looking for single files to recover, I just want to have it possible. I can make folder structure and separate backup tasks for pics, vids, graphics, music, documents, scripts, db etc.

Considering it is all uploaded to dropbox, I can download lets say 3x4GB files, open each archive and get only what I need. Still it is 12GB not 500GB to download.

Up to now, the best seem to be just to use encrypted dropbox and forget about larger chunks and splitting.

Regards

P.S. I found small piece of soft called DVDSPAN so maybe I could make ISO files + use boxcryptor.
 

USAFRet

Splendid
Moderator
How will you know which 4GB chunk the file in question is located in?

Compressing a bunch of small files into one medium size chunk leads to confusion when you need something back.
You need to back up individual files, individually accessible. No matter where you back them up to.
 

Beck76_Pitt

Commendable
Jun 3, 2016
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Hi,
I use Dropbox with Boxcryptor, because it keeps the structure of your folders. You can easily look for any file you want in the Boxcryptor drive.
I agree with USAFRet, if you split your data in chunks, it is hard to find something if you need it. And I really think it is not necessary.
With Boxcryptor you don't have to download all of the 500 GB, you can just pick the file you need.
As for corruption of files, I think Dropbox is really good at keeping your data safe, physically. I normally don't worry about files being corrupted. And Boxcryptor adds the privacy with encryption.
Good luck with your backup!
 

Whatlogin

Estimable
Apr 13, 2014
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Hi,

Thanks. Do not worry about my finding files :)

I am not native En, therefore I know what I want but find it hard to explain.

So my solution will be:

Make one time backup with split archive DL DVD size. I will use span disk option and create iso. Iso will be then encrypted with 7-zip by cobian backup and placed in dropbox.

The archive will have structure:
music: iso1, iso2, iso3, iso4.....
video: iso1, iso2, iso3, iso4....
svg.....
docs....

Then I remove this folder from sync and keep it in dropbox only.

I am not sure I am gonna need to download any file, but if I need my pictures bad and all my computers are down, I download only ISOs for pictures, not the whole archive. ISO and 7-zip are supported on any machine unlike backup software or boxcryptor.

Also if any ISO is broken, I loose this only ISO.

Next thing will be using Bxcryptor and make regular backup of files I work on daily basis and make no splits and all this combinations.

Thanks for all your posts.
Regards!

P.S. I do not understand windows7/8/10 it asks me for external disk, or can only backup system disk.

 

Whatlogin

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Apr 13, 2014
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Well encrypting, copying and upload or download 1000 files is more resource and time consuming. I will do it with regular backup rather than with one time backup. Plus compression of whatever can be compressed.

For example it is faster to download 2GB movie that 2gb of fonts in singe files.

Regular files - then off course no point of chunkin it.

Regards