Policy
Stop indexing in the event of limited hard drive space
Enabling this policy prevents indexing from continuing after less than the specified amount of hard drive space is left on the same drive as the index location. Select between 0 and 2147483647 MB. Enable this policy if computers in your environment have extremely limited hard drive space. When this policy is disabled or not configured, Windows Desktop Search automatically manages your index size.
9e2a7cc1d4bf StopIndexingOnLimitedHardDriveSpace Registry
Copy registry mappings
HKLM\SOFTWARE\Policies\Microsoft\Windows\Windows Search\PreventIndexingLowDiskSpaceMBPolicy notes
Enabling this policy prevents indexing from continuing after less than the specified amount of hard drive space is left on the same drive as the index location. Select between 0 and 2147483647 MB. Enable this policy if computers in your environment have extremely limited hard drive space. When this policy is disabled or not configured, Windows Desktop Search automatically manages your index size.