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IntroductionCustom container images Defining ImagesPrivate registriesFast pull from registryGPUs and other resources GPU accelerationUsing CUDA on ModalReserving CPU and memoryScaling out Scaling outDicts and queuesJob processingConcurrent inputs on a single container (beta)Dynamic batching (beta)Scheduling and cron jobsDeployment Apps, Stubs, and entrypointsManaging deploymentsInvoking deployed functionsContinuous deploymentSecrets and environment variables SecretsEnvironment variablesWeb endpoints Web endpointsStreaming endpointsWeb endpoint URLsRequest timeoutsWebhook tokens (beta)Networking Tunnels (beta)Proxies (beta)Data sharing and storage Passing local dataVolumesMounting local files and directoriesStoring model weightsDataset ingestionCloud bucket mountsNetwork file systems (superseded)Sandboxes SandboxesRunning commandsNetworking and securityFile accessSnapshotsPerformance Cold start performanceMemory Snapshot (beta)Geographic latencyReliability and robustness Failures and retriesPreemptionTimeoutsTroubleshootingSecurity and privacyIntegrations Using OIDC to authenticate with external servicesConnecting Modal to your Vercel accountConnecting Modal to your Datadog accountConnecting Modal to your OpenTelemetry providerOkta SSOSlack notifications (beta)Other topics File and project structureDeveloping and debuggingModal user account setupWorkspacesEnvironmentsJupyter notebooksAsynchronous API usageGlobal variablesRegion selectionContainer lifecycle hooksParameterized functionsS3 Gateway endpoints

Snapshots

Sandboxes support snapshotting, allowing you to save your Sandbox’s state and restore it later. This is useful for:

  • Creating custom environments for your Sandboxes to run in
  • Backing up your Sandbox’s state for debugging
  • Running large-scale experiments with the same initial state
  • Branching your Sandbox’s state to test different code changes independently

Filesystem Snapshots

Filesystem Snapshots are copies of the Sandbox’s filesystem at a given point in time. These Snapshots are Images and can be used to create new Sandboxes.

To create a Filesystem Snapshot, you can use the Sandbox.snapshot_filesystem() method:

import modal

app = modal.App.lookup("sandbox-fs-snapshot-test", create_if_missing=True)

sb = modal.Sandbox.create(app=app)
p = sb.exec("bash", "-c", "echo 'test' > /test")
p.wait()
assert p.returncode == 0, "failed to write to file"
image = sb.snapshot_filesystem()
sb.terminate()

sb2 = modal.Sandbox.create(image=image, app=app)
p2 = sb2.exec("bash", "-c", "cat /test")
assert p2.stdout.read().strip() == "test"
sb2.terminate()

Filesystem Snapshots are optimized for performance: they are calculated as the difference from your base image, so only modified files are stored. Restoring a Filesystem Snapshot utilizes the same infrastructure we use to get fast cold starts for your Sandboxes.

Memory Snapshots

Memory Snapshots for Sandboxes are in progress. Contact us if this is something you’re interested in!