Estimated size 30GB, actual size 11GB. What's missing?

[aaronrudkin]

Hey there,

I'm using your tool mostly to try to figure out what the hell is going on with my iCloud storage. I was hoping to do a single full export and then switch my iMessage settings to only preserve messages for a year. Apple thinks I have 37GB of messages in iCloud. My top conversations, which should be like 90% of my messages, say 16GB. When I run your tool, it claims it expects the export to be 30GB. The actual export is 11GB.

I have used about 4 phones and about 5 Macs over the period I've had iCloud message backups (2016 to present). I ran the application on a new M2 Macbook Air, but after about a week so there's been enough time to sync everything locally. Superficially, opening my conversations seems to show everything, so I can't actually tell what's missing.

I am wondering (a) what accounts for the difference between the export size and the projected export size; (b) whether this is a case that just the local computer hasn't synced attachments that should exist; (c) if there's any way to force this to happen so that the backup is a complete backup.

Thanks in advance for your time.

[ReagentX]

I don't know how Apple calculates the size.

imessage-exporter provides a rough estimate so writing the export does not exceed available disk space:

imessage-exporter/imessage-exporter/src/app/runtime.rs

Lines 221 to 258 in 2dc3d03

	/// Ensure there is available disk space for the requested export
	fn ensure_free_space(&self) -> Result<(), RuntimeError> {
	// Export size is usually about 6% the size of the db; we divide by 10 to over-estimate about 10% of the total size
	// for some safe headroom
	let total_db_size =
	get_db_size(&self.options.db_path).map_err(RuntimeError::DatabaseError)?;
	let mut estimated_export_size = total_db_size / 10;
	let free_space_at_location =
	available_space(&self.options.export_path).map_err(RuntimeError::DiskError)?;
	// Validate that there is enough disk space free to write the export
	if let AttachmentManager::Disabled = self.options.attachment_manager {
	if estimated_export_size >= free_space_at_location {
	return Err(RuntimeError::NotEnoughAvailableSpace(
	estimated_export_size,
	free_space_at_location,
	));
	}
	} else {
	let total_attachment_size = Attachment::get_total_attachment_bytes(&self.db)
	.map_err(RuntimeError::DatabaseError)?;
	estimated_export_size += total_attachment_size;
	if (estimated_export_size + total_attachment_size) >= free_space_at_location {
	return Err(RuntimeError::NotEnoughAvailableSpace(
	estimated_export_size + total_attachment_size,
	free_space_at_location,
	));
	}
	};
	println!(
	"Estimated export size: {}",
	format_file_size(estimated_export_size)
	);
	Ok(())
	}

The discrepancy you see is probably from attachments that are referenced in the table but are not present at the provided path. You can run with the diagnostic flag to get more information.