What is "diverse" backup?
I have backup options, advanced, validation set to "Validate the latest diverse backup version only." See attached file.
I cannot find a definition of what "diverse backup" means. Can anyone explain it to me?
So the "latest diverse backup" is simply the "latest backup?"
I was wondering if the word "diverse" somehow modified the meaning beyond simply the "latest?"
Robert, see the ATI 2021 User guide explanation of 'diverse' here:
You can specify the following settings:
- Validate backup each time after it is completed - Select to check the integrity of the backup version immediately after backup. We recommend that you enable this option when you back up your critical data or system disk.
- Validate the latest diverse backup only - A quick validation of the last backup slice.
- Validate entire backup
- Validate backup on schedule - Select to schedule validation of your backups to ensure that they remain "healthy".
- The latest diverse backup version when it is completed
- Entire backup when it is completed
The default settings are as follows:
- Frequency: once a month.
- Day: the date when the backup was started.
- Time: the moment of backup start plus 15 minutes.
You can also configure start of the validation manually from the backup context menu.
To do this, right-click the backup and choose:
- Validate all versions
- Validate last version
Example: You start a backup operation on July 15, at 12.00. The backup version is created at 12.05. Its validation will run at 12.15 if your computer is in the "screen saver" state at the moment. If not, then the validation will not run. In a month, August 15, at 12.15, the validation will start again. As before, your computer must be in the "screen saver" state. The same will occur on September 15, and so on.
You can change the default settings and specify your own schedule. For more information see Scheduling.
Steve, maybe I'm wrong... or maybe not.
If only the last slice is validated, that may be just an increment or differential without what is required before it to make it good. I assumed it was actually validating the backup through the last slice. For example, on an incremental it would be the entire .tibx file, but not any other prior .tibx files in the backup task.
I have not done any timing experiments to see what may happen.
Steve Smith wrote:Robert, see the ATI 2021 User guide explanation of 'diverse' here:
You can specify the following settings:
- Validate backup each time after it is completed - Select to check the integrity of the backup version immediately after backup. We recommend that you enable this option when you back up your critical data or system disk.
- Validate the latest diverse backup only - A quick validation of the last backup slice.
- Validate entire backup
- Validate backup on schedule - Select to schedule validation of your backups to ensure that they remain "healthy".
- The latest diverse backup version when it is completed
- Entire backup when it is completed
The default settings are as follows:
- Frequency: once a month.
- Day: the date when the backup was started.
- Time: the moment of backup start plus 15 minutes.
You can also configure start of the validation manually from the backup context menu.
To do this, right-click the backup and choose:
- Validate all versions
- Validate last version
Example: You start a backup operation on July 15, at 12.00. The backup version is created at 12.05. Its validation will run at 12.15 if your computer is in the "screen saver" state at the moment. If not, then the validation will not run. In a month, August 15, at 12.15, the validation will start again. As before, your computer must be in the "screen saver" state. The same will occur on September 15, and so on.
You can change the default settings and specify your own schedule. For more information see Scheduling.
In the above, the word "diverse" is used but is not explained. The term "slice" is also not explained. A search of the help text shows only the above and no place where those terms are explained.
I think I might be able to guess "slice" refers to the incremental (or differential?) data as opposed to the complete image.
My understanding here is that a 'slice' is simply that specific backup action, i.e. to create either an incremental or differential backup (that in earlier versions would have been a separate file) and in the context of this discussion, validating only the diverse slice will only operate against the same without validating the backup chain that the slice is an integral part of.
Personally, I do not use validation as it doesn't prove anything more than 'what was written to disk is the same as is still present on disk'. It gives no guarantee that the backup chain will yield a successful recovery which only doing a restore of the contents can show!
From the perspective of the new .tibx format files, I have greater confidence in the integrity of the chains of incrementals by virtue of these being consolidated within a single file and thus being less susceptible to accidental deletion or damage to individual 'slice' files. I don't use differential backups other than for testing other user scenarios, especially with .tibx chains due to the increased interdependence between all files.
Steve,
That all makes a lot of sense! thanks.
The wording is probably left over from the earlier, multi-file, design. I think I will ignore my confusion over it -- and turn off validation.
I just did a timing experiment. I created a new Incremental Disk/Partition backup of the C: drive using the option to validate the latest diverse backup only.
First backup (Full):
Data to Recover: 56.8 GB, Backed up: 29.2 GB
Time to do the full backup: 37 minutes
Time to do the validation: 7 minutes
Second backup (Incremental):
Data to Recover: 56.8 GB, Backed up: 172.6 MB
Time to do an Incremental backup: 22 minutes
Time to do the validation: 7 minutes
So, although the second backup was a very small addition, the validation was most likely to the entire backup and not just the small 172.6 MB slice.