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W&B stores artifact files in a private Google Cloud Storage bucket located in the United States by default. All files are encrypted at rest and in transit.

For sensitive files, we recommend you set up Private Hosting or use reference artifacts.

During training, W&B locally saves logs, artifacts, and configuration files in the following local directories:

FileDefault locationTo change default location set:
logs./wandbdir in wandb.init or set the WANDB_DIR environment variable
artifacts~/.cache/wandbthe WANDB_CACHE_DIR environment variable
configs~/.config/wandbthe WANDB_CONFIG_DIR environment variable

Depending on the machine on wandb is initialized on, these default folders may not be located in a writeable part of the file system. This might trigger an error.

Clean up local artifact cacheโ€‹

W&B caches artifact files to speed up downloads across versions that share files in common. Over time this cache directory can become large. Run the wandb artifact cache cleanup command to prune the cache and to remove any files that have not been used recently.

The proceeding code snippet demonstrates how to limit the size of the cache to 1GB. Copy and paste the code snippet into your terminal:

$ wandb artifact cache cleanup 1GB

How much storage does each artifact version use?โ€‹

Only files that change between two artifact versions incur a storage cost.

v1 of the artifact "dataset" only has 2/5 images that differ, so it only uses 40% of the space.

For example, suppose you create an image artifact named animals that contains two image files cat.png and dog.png:

|-- cat.png (2MB) # Added in `v0`
|-- dog.png (1MB) # Added in `v0`

This artifact will automatically be assigned a version v0.

If you add a new image rat.png to your artifact, a new artifact version is create, v1, and it will have the following contents:

|-- cat.png (2MB) # Added in `v0`
|-- dog.png (1MB) # Added in `v0`
|-- rat.png (3MB) # Added in `v1`

v1 tracks a total of 6MB worth of files, however, it only takes up 3MB of space because it shares the remaining 3MB in common with v0. If you delete v1, you will reclaim the 3MB of storage associated with rat.png. If you delete v0, then v1 will inherit the storage costs of cat.png and dog.png bringing its storage size to 6MB.

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