Mirror backup vs incremental backup
GM3 Posted messages 140 Registration date Status Membre Last intervention -
Hello,
I have only ever used Windows backup or Norton, the latter being incremental.
If I understand the differences correctly, if I need to restore my PC with a mirror backup set, I will have to restore it with both the initial backup and the last one; whereas with an incremental backup set, I would have to restore everything (I can already imagine doing that...).
Is it really that way? Because if so, I would definitely prefer mirror backups (when I delete a folder or file from the source, it’s because I no longer need it).
And in operating this way, is Synckback Free or Easy Backup better? (I will choose one of those two).
Thank you for your responses and have a good afternoon.
3 réponses
Hello,
Incremental backup is a legacy from the time when backups were made onto tape or cassette. Access to backups is only through the software, but multiple versions of the same file can be retrieved.
Mirror backup (like the one from syncbackfree) is directly accessible, but it only has one version of the file. To have versions from different dates, multiple backups are required.
I use syncback and have 3 distinct backups, 2 external HDDs, and a NAS. The ideal situation would be to have a backup located elsewhere, like a HDD in another location, or a cloud backup.
Hello,
The term "mirror backup" is commonly used for system images; they reflect, like a mirror, the contents of the source at a specific moment. By definition, the system image backs up the entire system disk.
Even if I were to create several of these images, I would only be able to restore one.
When talking about Syncback and similar tools, we're referring to data backups.
If I create several successive total data backups, each contains the entirety of the source at the time it was created: only the last one will return the current data to me; the previous ones, whether it's the first or others, can only be used to recover old deleted data and are unusable if they follow the all-or-nothing rule.
Incremental backup (which is a "mirror" backup but only of the data), after an initial copy, adds to the destination what has been in the source and deletes what no longer exists there, except for security measures, so only one is needed; this is the case with Syncback.
Some backup schemes mix genres a bit; for example, we keep the incremental backups from the last 3 days, each providing the "mirror" for that day: this is a safeguard against errors where today I might have accidentally deleted or corrupted what was working yesterday since nothing prevents me (if the backup format is native) from only retrieving a single file if necessary.
Good evening,
And thank you both for your responses.
So if I do an incremental backup (only of data: my main folders, photos, etc.), can I restore based on the last date of this backup set?
Will I only have one option available? (one backup set on day 1 modified with each additional backup).
Yes to the first question, but of course we recover the files not in their current state, but in the state they were at the time of that backup; in my opinion, it should be done every day.
The second one depends on the options of the script or software used: if you create multiple backups, nothing prevents you from restoring an older one (which will therefore not be up to date by design).
As I said, if the script or software backs up in native format and not in a proprietary format, nothing prevents me from not restoring anything at all but simply overwriting a current file that has failed with a copy-paste of the one from one of the backups.
If I understand correctly, the first backup is the entirety (of what I chose to back up) and the subsequent ones (on the same backup set) add new files/folders or those that have been modified and remove the files that I have deleted?
I'm talking about mirror backup here.
If that's the case, it's exactly what I'm looking for (I just checked in Norton and it would take quite a while to restore).
In mirror you have the complete image of your last backup. And yes, the first operation involves all the files, then the software only processes the delta. I don't know about Norton (which may create a compressed or encrypted backup), but Syncback backs up the entire directory structure directly accessible to another location.
"Restoration length" depends on the volume ;-) I have a 4TB backup from my NAS, and it's certain that if I had to reconstruct it, it's not instantaneous.
Hello,
So I downloaded Synckback and I have a quick question (if I’m not being too much of a bother): when I run the installation just for me, the program wants to install in Appdata, and if it's for everyone, it goes in C/program(x86); that's more standard.
It’s a bit of putting dots on the i’s, I admit, but is there an advantage to installing it just for me, in Appdata? (I find it a bit unusual: I’ve only seen that once with Sumatra PDF).
Now, it's not too important since I'm the only user on this PC, but I like to understand.
Have a good day everyone and thanks for the feedback
Message without subject I found on TopTips.Fr:
"When an application is installed on Windows 10, it registers files in two different locations: Program Files or Program Files (x86) and the AppData folder. This is true for most applications, but some applications install only in the AppData folder, while others install only in Program Files or Program Files (x86), and not in AppData."
Thanks to everyone for enlightening me: I will try Synckback Free