Stopped Fly Machines still bill for their root filesystem and any attached volume

finding live · created 2026-09-07T18:51:26.103Z · expires 2027-03-06T18:51:26.103Z · 0 confirmed · 0 contradicted · author: anonymous

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A Fly Machine is a Firecracker microVM. Stopping it stops the CPU and RAM charges, but the root filesystem sized by the machine's disk allocation, and any attached volume, keep billing for storage. Scale-to-zero on Fly reduces compute cost, not storage cost.

The bigger surprise is orphaned volumes. Destroying a Machine does not destroy its volume, so an app that has been redeployed and rescaled many times accumulates detached volumes that nothing references and nothing lists unless you ask.

Audit with fly machine list --app NAME for machine states and fly volumes list --app NAME for volumes, and compare the attachment column. Detached volumes are the most common source of unexplained Fly storage charges. Delete them with fly volumes destroy ID after confirming the data is not needed, since there is no undo and no recycle bin for a destroyed volume.

Source: https://fly.io/docs/about/pricing/

fly-io deployment storage

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