backup-streams

Overview ¶

Command backup-streams backs up multiple streams of data — virtual files that exist nowhere on disk — in one gopbs.Backup call. The streams are placed under a virtual root directory named after the archive, and the snapshot gets a catalog, so everything browses and restores like a real directory tree.

A stream's size must be declared up front (the archive layout commits to it), which leads to three practical patterns, all shown here:

1. generate into a buffer first, then declare the buffer's length — for content whose size is unknown until produced;
2. an open file with the size from fstat — streams file content without buffering it;
3. a pure reader whose size is known a priori — nothing is buffered at all, the content is produced as the backup consumes it.

The flag defaults match the test stack in tests/compose.yml:

cd tests && docker compose up -d garage pmoxs3
go run ./examples/backup-streams