Modification timestamps

[Akita]

Hi All,
I’ve been using veracrypt for years and recently updated one of my containers with important information, ran a backup and felt good about being secure and backed up. Than clicked into the “Completed x mins ago” to verify it got uploaded…this is where the problem begins!, It wasnt uploaded. noticed in Veracrypt that theres an option “Preserve modification timestamps of file containers”, oh noes…this is default on.
So now i have many containers that are “out of sync” with my b2 backup, which is sub-optimal. i see there is a -hash option and found 2 forum posts, but they didnt really give me the information im after.
Basically id like to know/understand - whats my best option here?. i think id be a good idea for me to run a “-hash” job ever so often to ensure i capture everything?. How much performance hit will this give, i suspect itll hammer my SSD.
Also how does one run a hash job every so often? just add it in the “Command options” or “Global options” in the web gui for when i run a backup and remove it once its done? will doing it this way create issues?
i could change veracrypt, but i think id feel better doing a -hash every so often as maybe theres other programs that are doing this to my files too.

other topics i looked at for informational purposes.

Why do -hash backups show every single file being uploaded?

I’ve switched to using -hash backups since it seems more accurate and it doesn’t take much time for me. One thing that confuses me though is that in the log I see “INFO UPLOAD_FILE” for every single file, even ones that definitely haven’t changed since the last backup. In the summary it does say that only a few new chunks were uploaded, but it also says that every file was new. Is this some logging issue or what is going on here?

Should we use -hash with every backup?

With the -hash argument Duplicacy will need to read the entire content for each file, and this can be very slow for a large directory. That is why it is not enabled by default. Without the -hash argument, Duplicacy will only back up files with different timestamps from last backup. This may be a problem if there is some file whose content has been modified but the modified time somehow remains unchanged. Another less obvious problem without the -hash argument is that it may leave ‘holes’ in …

[saspus]

Creating backup of an encrypted veracrypt container is a horrible idea from space utilization perspective. Single byte change in the data results in massive change in the container, by design.

Instead, you may want to backup data in the container itself. Mount it, backup, and unmount.

using hash is a bandaid and can lead to even higher space usage, and resource utilization.

[Akita]

thanks for your reply and i appreciate your input.

I understand that from duplicacy point of view these containers are a bad idea. (and from a space utilization).
But from my own point of view, and a security point of view these are great and work perfectly for my purpose.
I have approx 20 different containers, that remain untouched 95% of the time. they contain various old files from my past. I’d like them to stay locked away and encrypted, even from physical attacks (access to my laptop/hdd), Today i opened one container (thats 10MB) to update a very important file.
most of what i backup is unencrypted. But these containers contain important data, which doesn’t change very often at all. having to mount and backup and unmount that many containers is extremely time inefficient and increases security risk, these dont need to be opened 95% of the time, but very rarely do.

Its one of my requirements for my backup software to be able to backup these. but also maybe theres other software not updating timestamps too, this is only the first one i found. to mitigate not having all my backup data i figure the “-hash” would be good to run on a 6 monthly basis maybe?(thus my previous questions in my last post)

[saspus]

yes, you can run with -hash, with this in mind:

Should we use -hash with every backup?

With the -hash argument Duplicacy will need to read the entire content for each file, and this can be very slow for a large directory. That is why it is not enabled by default. Without the -hash argument, Duplicacy will only back up files with different timestamps from last backup. This may be a problem if there is some file whose content has been modified but the modified time somehow remains unchanged. Another less obvious problem without the -hash argument is that it may leave ‘holes’ in …

@Akita

But from my own point of view, and a security point of view these are great and work perfectly for my purpose.

It limites possible backup history unless you have unlimited storage capacity. Duplicacy supports encryption, so there is really no need to wrap stuff into another layer. But it’s up to you of course.