Get-DbaBackupInformation - Fix size information for striped backups

[andreasjordan]

Type of Change

• Bug fix (non-breaking change, fixes Get-DbaBackupInformation - Sizes are incorrectly summed #8302 )
• New feature (non-breaking change, adds functionality, fixes # )
• Breaking change (effects multiple commands or functionality, fixes # )
• Ran manual Pester test and has passed (.\tests\manual.pester.ps1)
• Adding code coverage to existing functionality
• Pester test is included
• If new file reference added for test, has is been added to github.com/dataplat/appveyor-lab ?
• Unit test is included
• Documentation
• Build system

Every file of a striped backup contains the size information about the backup itself, not the individual file. So the size can just be fetched from the first backup file like most other information.

Before:

After:

[potatoqualitee]

ahhh now i remember! this is TotalSize vs Size -- that's why the TotalSized is summed. Can you do that? We may need an Add-Member

[andreasjordan]

ahhh now i remember! this is TotalSize vs Size -- that's why the TotalSized is summed. Can you do that? We may need an Add-Member

Sorry, I don't understand. Can you explain?

[potatoqualitee]

Your PR proposes to change the value of the TotalSize column. The TotalSize column was intended to be a summary size of the whole backup, not the file itself, which is why it's called TotalSize and not Size.

So we can add a backup size for the individual file, it'll just have to be a differently named column, perhaps Size.

[andreasjordan]

The output of Get-DbaBackupInformation does not list information about individual files. A striped backup only has one object returned. That is done via the Group-Object.

Some pictures...

I have taken two backups of Adventureworks:

The filesystem says:

The command says:

So in case of the striped backup, both files of around 100 kByte are part of same backup and their headers include the information "Backupsize = 200 kByte". The size of the file is not found - and not needed, as we don't return information about files.

So we only have - and only need - one "Size" information, currently named "TotalSize" (and one for the compressed value named "CompressedBackupSize").

So I still think my PR fixes a bug.

[potatoqualitee]

@ClaudioESSilva and i are still working through this as I still need convincing there should not be a totalsize AND size and im doing a sanity check 😊

[potatoqualitee]

i cant get the numbers to be different so this works for me since it works for yall 😅