oxidecomputer / oxidecomputer/crucible
snapshots need additional space reservation while the scrubber works.
Nobody has claimed this yet.
- Dominant language
- Rust
- Stars
- 260
- Forks
- 34
- Avg merge
- 2d 1h
- Merged PRs (30d)
- 8
Description
To make a snapshot, we create a destination region first.
After creating the snapshot, while the scrubber copies data from snapshot to the
eventual backing downstairs region, we need a temporary space reservation in
Nexus to allow for the original volume to be written to without running out of space.
Due to the copy on write snapshot feature of ZFS, it's possible for the original volume
to take writes that will grow the total space required for snapshot+source in a way we
don't currently account for.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by tracing snapshot creation, the scrubber, and the Nexus space-management path described in the issue. Determine where the temporary reservation belongs and how it should be released after copying; done means copy-on-write writes to the original volume cannot exhaust space during snapshot processing.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- backend, infrastructure
- Issue type
- Feature
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 25/100