ExFAT Lost Disk Space

[SeanF]

Hi:

I am not sure what forum this belongs in but this seemed like the best fit

I have two identical 4TB USB hard drives which I need to be able to be read by both Mac and Windows operating systems. The first one was formatted one as Mac OS Extended (Journaled) and I copied about 1.0 TB or data onto it. Then I realized I should have formatted it as ExFAT. So, I formatted the second one as ExFat and copied all of the data from one drive to the other. (That process took forever)

The issue is that on the ExFAT disk, the same data takes 1.5 TB. So, I used OmiDiskSweeper to evaluate both drives and find that on the ExFAT drive, the smallest file size is 1.0 Mb. On the MacOS disk, the smallest file size is 8.2kb. The same file on the ExFAT is 1.0Mb. I assume this is because of the minimum block size when the disk was formatted.

I really don't want to waste 0.5TB (more once the disk has more data).

Is this the block size the problem?
Can I change that without reformatting?
Is there something else I can do?

Thanks

[tangor]

It's all based on cluster size ... there's a chart on this page:
[support.microsoft.com...]

[SeanF]

OK, Thanks for the reply... But can I change the cluster size to save disk space or do I need to reformat the disk?

[tangor]

Read the chart ... it is all based on those metrics. In real life it usually evens out. Depends on the file sizes you deal with on a regular basis.

[SeanF]

Thanks. But that doesn't answer the question of whether I can change minimum cluster format without reformatting the disk.

I reformatted the disk