Large backup to FAT does not warn user of unsuccessful backup

[janvlug]

• I have searched open and closed issues for duplicates
• I am submitting a bug report for existing functionality that does not work as intended
• I have read https://github.com/signalapp/Signal-Android/wiki/Submitting-useful-bug-reports
• This isn't a feature request or a discussion topic

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Bug description

When you create a backup of a large > 4.3 GB Signal database to an as "portable" formatted (I guess FAT32) SD-card, a partial backup file is created of 4.3 GB instead of a full backup. The user does not get a warning, and thinks that they have a good backup, which is not the case.

The restore of the partial backup did not get messages back, changed my safety number and disconnected my linked devices.

I consider this as a very severe issue, because I lost all history while I thought that I made a valid backup.

Device info

Device: Nokia 4.2
Android version: 11
Signal version: 0.0.0

Link to debug log

[Meteor0id]

Also (reported before) unsucesful backup files do not get cleaned up, and thus fill up the storage even further. Even disabeling backups does not clear partial backupfiles like it would with completed backup files.

[Roghetti]

I already opened a pull request to address this: #11900
It is about backup-chunking and splits the backup into 1GB parts to prevent to run into the FAT32-file-size-limit issue.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been closed due to inactivity.

[janvlug]

I'm pretty sure that this issue has not been resolved. Re-opening would be appreciated.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[janvlug]

This issue is still there.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[michikommader]

Still open and still a severe issue.

[janvlug]

I'm running again into this issue. I created a forum topic to discuss it further.