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Version: 1.0.0

How to Choose Compression

Select between gzip and zstd compression when pushing images.

Prerequisites​

  • blobber installed
  • Registry access configured

Available Algorithms​

AlgorithmFlag ValueBest For
gzipgzip (default)Maximum compatibility
zstdzstdFaster decompression, better ratios

Using gzip (Default)​

Push with default compression:

blobber push ./data ghcr.io/myorg/data:v1

Or explicitly:

blobber push ./data ghcr.io/myorg/data:v1 --compression gzip

Using zstd​

Push with zstd compression:

blobber push ./data ghcr.io/myorg/data:v1 --compression zstd

When to Use Each​

Use gzip when:​

  • You need maximum registry compatibility
  • Other tools will read the image
  • You're unsure which to choose

Use zstd when:​

  • You control the entire workflow
  • Decompression speed matters
  • You're storing large files

Verification​

The compression algorithm is stored in the image. To verify:

blobber list ghcr.io/myorg/data:v1

Both algorithms produce valid eStargz images that work with list, cat, and pull.

Notes​

  • You cannot change compression of an existing image
  • Push a new tag if you need different compression
  • Compression choice doesn't affect file listing or selective retrieval

See Also​