osQuery Management Server (Prime).Available Disk Space (Windows) (SQLite SQL Statements)
SELECT
ROUND((sum(free_space) * 100 * 10e-10) / (sum(size) * 10e-10)) AS percent_disk_space_available,
ROUND(sum(free_space) * 10e-10) AS gigs_disk_space_available,
ROUND(sum(size) * 10e-10) AS gigs_total_disk_space
FROM logical_drives
WHERE file_system = 'NTFS' LIMIT 1;