Rclone is to cloud storage what a Swiss Army knife is to everyday tasks: a single command-line tool that operates more than seventy storage services and protocols in a uniform way, from an S3 bucket through Google Drive to an SFTP server. It is the de facto standard whenever data has to be moved between local systems and clouds in a scriptable way.
Articles on Rclone (3)
Remotes: the basic idea
Rclone abstracts every service as a remote: a named configuration with a backend type and credentials, created through the interactive rclone config dialog. After that, all services are addressed identically (remote:path), and commands work across backends, including cloud to cloud. Remotes can be stacked: a crypt remote is layered on top of any other one and encrypts file names and contents on the client side before they leave the machine; the service behind it sees only random data.
The core commands and their semantics
copy transfers files, overwrites nothing newer and never deletes. sync makes the destination match the source exactly, including deletions; the direction is part of the command and warrants corresponding care (--dry-run shows in advance what would happen). mount exposes a remote as a file system and brings cloud storage to applications that only understand file paths; caching modes control the trade-off between compatibility and immediacy. check compares source and destination by checksum or size and answers the question of whether a transfer really was complete and intact. Everyday helpers such as lsd, lsl, size and ncdu round out the set.
Operational characteristics
Rclone transfers in parallel, resumes interrupted runs idempotently and respects bandwidth and transfer limits (--bwlimit, --transfers). Filter rules include or exclude paths. For services with API quotas, Rclone throttles itself on request, which permits continuous operation alongside productive use. For unattended deployment there are structured logs and a remote control mode with an HTTP API; in containers Rclone runs as a sidecar or mount service, where mounts demand particular attention to startup order and permissions.
Assessment
The tool reaches its limits where services offer no API or only unofficial ones, or where end-to-end encryption rules out access by third-party clients; there, solutions often appear only with a delay or by way of workarounds. Within its field, Rclone is regarded as mature, conservatively maintained and unusually well documented.
