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Can the hidden 10 percent disk space reserved for WAFL be adjusted?

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Applies to



The "hidden" 10% of disk space reserved for WAFL cannot be adjusted, nor can the root user create files in the hidden space.

The file system is more efficient when no more than 90% of the physical capacity it occupies is allocated for storing data and metadata. The major advantage is that with one block in every ten always free, the filer is able to locate free space more efficiently, and also have more flexibility in how data is placed to optimize disk writes.

Additional Information

Beginning ONTAP 9.12.1, the WAFL reserve for aggregates greater than 30TB is reduced to 5% for All Flash FAS (AFF) and the FAS500f platforms. 


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