Fixes bug where additional disks added twice

[josh-barker]

Description

• Fixes bug where additional disks added twice
• Refactor mounting iso method
• Don't attach disks that have a size <= 0

Check List

• [x] All tests pass.
• [ ] All style checks pass.
• [x] Functionality includes testing.
• [ ] Functionality has been documented in the README if applicable

[jjasghar]

Can one of the admins verify this patch?

[jjasghar]

Can one of the admins verify this patch?

[jjasghar]

ok to test