• The zlib library accepts a deflate factor of 0 through 9.
• We do not always see much difference in compression by using higher numbers for the deflate factor, but there is certainly a performance penalty.
• Therefore we suggest trying deflate level of 1 or 2. You may have different results.
• Compression cannot be used when writing data with parallel I/O. (It can be used when reading data with parallel I/O.)
• The HDF5 library also offers szlib compression, based on the szlib compression library. Since this library has some license restrictions (for commercial users creating datasets), we don't support creating szlib compressed data.
• The nccopy utility can apply a uniform level of compression to all the variables in a file. Use nccopy to experiment with whether compression is worthwhile, and what level is optimal.

2012 Unidata NetCDF Workshop > Chunking and Deflating Data with NetCDF-4