Backup Types [fuller] Description

I am reading the fine manual (RTFM) and I would like some interpretations by someone at WD or someone very versed in how these “types” work:

Copy - Copies files from Source to destination. Duplicate files will not be overwritten. …by duplicate files does this mean exact duplicates (identical) or does this mean files with the same name?

Synchronize - Copies files from source to destination. Duplicate files WILL BE overwritten. …I saw somewhere else on the forum that this means that new files will be added and existing files will be over written. By existing, here I assume we are referring to files with the same name which may or may not be identical in content.

Incremental - Copies incremental changes of files up to 25 copies to the destination. Does this mean I would wind up with multiple copies of a file with the same name if that file had been edited or updated?

Thank you.


I recommend you contact WD support directly for assistance with this issue.

Hi Jblane001, Your question is very straight forward and if you get the answer from WD please share with the community. Meanwhile this is what I believe them to mean:

Copy - I understand this to mean copy the source whenever you backup. Each time it will be put into a different folder therefore not over-writing what was back-up previously.

Synchronize - Means at the end of a back-up both source and destination will be identical. Anything in the destination which is no longer in the source will be deleted.

Incremental - It should mean you end up with one complete set of files identical to the source, with up to 25 versions if the file had changed since the last backup took place. You may have noticed from another thread an open issue with incremental back-ups. From my personal experience it meant 25 complete copies of the source no matter if the file changed or not. I took this up with WD support to be told to restore my device to default. This would have lost my settings for my remote back-up which I didn’t want to do as it took an age to set that one up. So still unresolved.

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Thanks, I’m going to submit this question to WD Support and see what they say. It’s been decades since I was a System Operator on a “minicomputer” system running VMS or UNIX. But in that environment, there were two types of backups: fulls and incremental. A full was a complete, albeit compressed, copy. An incremental was a copy of only what had changed since the last backup (regardless of whether that backup was a full or incremental). In order to recover to a particular date, you first applied the previous full backup and then applied each incremental until you got to the desired date. A little labor intensive in the case of a loss, but it saved space since you weren’t backing up everything in between. Using that strategy and compression, your backup space did not need to be larger than your online space even though you might be maintaining the capability to roll back an entire year. Typically the schedule was a monthly backup and weekly or daily incrementals depending on how volatile the data was. For a software development area, incrementals were daily so that we could recover to yesterday at any time. For our releases and online reference stuff incrementals were weekly or even less since the information hardly ever changed.

Thanks, I’m going to submit this question to WD Support and see what they say.

Through support escalation I now understand what is happening when you set up an incremental backup - I have written it up on the following topic - Incremental Backup is working like differential Backup - #7 by PtM

I’ve had the same issue and done some tests.

Copy - Files are not overwritten, therefore when files change the newly changed file will be saved as “somefile_1.txt”, “somefile_2.txt”, … etc. when “somfile.txt” is deleted, it is not deleted from the backup directory. I would not recommend this for creating a copy of data where files changes, due to the extra copies every time a file changes.

Sync - Files are overwritten, therefore when a file changes the newly changed file will overwrite the existing file. When files are deleted they are also deleted from the backup directory during sync.
This is good for user directories with a lot of changes.

Incremental - This one is interesting. So every time there is a backup, a new folder is created with a timestamp. The folder contains a copy of the content, similar to the result from using sync.
Incremental saves up to 25 folders, after this point the oldest folder is deleted.
This is good for user directories with a lot of changes, but when you also want to be able to go back to see how it looked a few backups ago.
From Windows the directory appears to be 25 the size. So in my case, the source folder is ~40gb and with 11 copies ~440gb, but looking through WD’s web UI, it says the directory is only ~40gb. Most likely what is happening is that WD is creating a link between the identical files so they don’t actually take up space, except for storing the deleted files from the last 25 backups.