Add support for Discard operations
Nobody has claimed this yet.
Assessment
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Newbie friendliness
- 48/100
- Issue type
- Feature
- Clarity
- Mostly clear
- Activity status
- Quiet
- Tech stack
- rust
- Domain
- distributed-systems
Research direction
No files or tests are named. Start by tracing how Crucible handles Discard operations and how those operations reach the underlying files, using the local-storage behavior described in the issue as context. Done means Discard is plumbed through Crucible and the underlying files receive the intended fcntl(F_FREESP) handling.
Written by the indexing model from the issue text.
Description
With the support of NVMe Discard operations introduced by https://github.com/oxidecomputer/propolis/pull/1105, Propolis accepts Discard operations for all disk types. For local storage, the Discard operation is passed down to the ZFS raw zvol via ioctl(DKIOCFREE), which will issue a Discard on the underlying physical SSD. But for Crucible disks, the Discard operation is a no-op. We should consider plumbing the Discard operation through Crucible and having it issue a fcntl(F_FREESP) to the underlying files.
The benefit of processing the Discard is similar for local storage and Crucible: although it doesn't make the space available to other uses (because the space that may potentially be used for the Crucible disk remains reserved), it reduces the allocation and fragmentation burden on the underlying subsystem (the SSD's FTL in the case of local storage, or ZFS's metaslab allocator in the case of Crucible).
- Dominant language
- Rust
- Stars
- 260
- Forks
- 34
- Avg merge
- 2d 1h
- Merged PRs (30d)
- 8
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.
More from oxidecomputer/crucible
-
atty is unmaintained Open
Difficulty 2/5 1-3 hours Newbie friendliness 84/100
oxidecomputer/crucible#1959 ·
-
Difficulty 2/5 1-3 hours Newbie friendliness 58/100
oxidecomputer/crucible#1958 ·
-
oxidecomputer/crucible#1955 · 1 assignee ·
-
Difficulty 4/5 3-5 days Newbie friendliness 35/100
oxidecomputer/crucible#1951 ·
-
oxidecomputer/crucible#1944 · 1 comment · 1 assignee ·
All issues in oxidecomputer/crucible
Similar issues
-
Difficulty 2/5 1-3 hours Newbie friendliness 86/100
kwakseongjae/auto-hwp#319 ·
-
area:cli bug filter-quality good first issue priority:medium
Difficulty 2/5 1-3 hours Newbie friendliness 84/100
-
Difficulty 1/5 Under an hour Newbie friendliness 72/100
bevyengine/bevy#25861 ·
-
comp-datalake
Difficulty 2/5 1-3 hours Newbie friendliness 88/100
ClickHouse/ClickHouse#121222 ·
-
enhancement remote
Difficulty 2/5 1-3 hours Newbie friendliness 68/100