Exact mirror + reverse incremental

[Shaipetit]

I'd like to suggest a new feature for Syncovery.

Syncovery could implement Exact Mirror + Reverse Incremental sync operation mode.

An incremental backup of the changes made between two instances of a mirror is called a reverse incremental. By applying a reverse incremental to a mirror, the result will be a previous version of the mirror. In other words, after the initial full backup, each successive incremental backup applies the changes to the previous full, creating a new synthetic full backup every time, while maintaining the ability to revert to previous versions. The main advantage of this type of backup is a more efficient recovery process, since the most recent version of the data (which is the most frequently restored version) is a (synthetic) full backup, and no incrementals need to be applied to it during its restoration.

At first a full backup is made. But when the following backup is created, first all data from the full backup is moved to this new backup and the previous one is replaced with a small reverse incremental version. The old backup then contains only the differences to the following backup (in contrast to normal incremental systems, where each backup contains the differences to the preceding backup).

One effect of reverse incremental storage is that the newest backup is always a full backup.

Advantages

Faster restore:
With normal incremental systems the data of the newest backup is spread out over many backup versions. This slows down the restore process considerably. With reverse incremental storage this data is stored in one block in the latest backup version and fast access is possible.

Higher data safety:
The most valuable data of a backup is always the latest data. With normal incremental storage the latest backup depends on all preceding backups. If any one of these is damaged then all following backups will be broken, including the most recent one. In a reverse incremental system the newest backup is completely independent of all other backups. If an old backup is damaged then only the preceding backups are affected, but not the more valuable newer backups.

Simpler storage management:
With reverse incremental backups the oldest backup can safely be deleted at any point in time. The following backups are not affected by that at all. This enables fine-grained storage management that can also be automated easily. Even if the destination drive is completely full the solution is very simply: simply delete the oldest backup.

There is a program called AllSync, which has implemented Exact Mirror + Reverse Incremental approach, however AllSync doesn't natively support LAN, WAN, cloud destinations, doesn't handle Unicode. Syncovery beats AllSync hands down in other fronts.

Would it be possible for Syncovery to implement Exact Mirror + Reverse Incremental option?

Thank you.

[superflexible]

Hello,
many thanks for the suggestion! I will take a close look at how this can be done next year.

[Shaipetit]

Thank you for your consideration!

By the way, here's a nice short animation highlighting the advantages and benefits of reverse incremental (decremental) backup algorithm:

https://www.youtube.com/watch?v=9PqZkM6RerU