Making room#

Remove, by hand and with every writer stopped, the two kinds of file a store may lose before swarmops gc exists. Commands and outputs here follow the conventions of the operations guide.

What may go#

A store only grows (Limits): nothing is collected until M6's swarmops gc. Two kinds of file in it may go by hand meanwhile, with every writer stopped. This is what the storage spec gives for each, and no more:

The leftovers of interrupted writes, files in objects/tmp/ and meta/derived/tmp/. A write stages its file there and links it into place, and a writer that dies on the way leaves the file. The spec has a crash before the frame that names an object leave only orphan objects and temp files, and no frame names an object before it is linked and durable (§2, rules 1 and 2), so a staging file is never the only name of an object that a changeset needs. swarmops gc is to clear the files of objects/tmp/ that are older than an hour (§2) and the temp files of meta/derived/ (§3). By hand, remove the files older than an hour, and not the directories: the spec lists them as part of the layout, and does not say that a store makes them again.
The derived values, meta/derived/, which may go whole. They are a cache that neither the journal nor any other file names (§3), and removing a value's file, or meta/derived/, makes the value derived again (§5).

The orphan objects stay: telling them from the objects a changeset names takes the mark and sweep from the journal that gc gets later. The objects, the journal, the index and the refs stay as they are.

1. Stop every writer#

Both removals need the store to themselves. A writer is every process that can write it: the agents' sessions and their MCP servers (a server lives as long as its session), the loop's commands and swarmops derive, and also a read, which stores the values it derives. flock on meta/lock stops none of them, since objects and derived values are written without it. Check that no swarmops is left (so is the same program):

pgrep -ax 'swarmops|so'

1503 swarmops mcp --repo …

That is an MCP server that a client started for its session: end the session. With nothing left, the command prints nothing and exits 1.

2. Remove the leftovers of interrupted writes#

From the store's directory (the :? refuses an empty variable, which cd would take for the current directory), the leftovers (on a store that never derived a value, find says that meta/derived/tmp does not exist, which is right):

cd "${SWARMOPS_REPO:?}"
find objects/tmp meta/derived/tmp -type f -mmin +60

objects/tmp/.tmpUbSpKg
meta/derived/tmp/3849408-0-ffc434ac1bd4cb92

This store had three leftovers of writers that were killed in the middle of a write; two were set back a day with touch -d, to have the hour pass, and the third is as young as it was. The removal leaves that one:

find objects/tmp meta/derived/tmp -type f -mmin +60 -delete
find objects/tmp meta/derived/tmp -type f

objects/tmp/.tmpoyk2fg

3. Remove the derived values#

The derived values come off whole, and verify --deep has no stored value left to check:

du -sh meta/derived; find meta/derived -type f | wc -l
rm -rf meta/derived
swarmops verify --deep

344K	meta/derived
38
{"ok":true,"op":"verify","api":1,"result":{"objects_checked":45,"changesets_checked":15,"problems":[],"findings":[]},"meta":{"repo":"…","elapsed_ms":2,…}}

4. Derive them again#

A read derives the values it needs and stores them in a meta/derived/ that it makes again, swarmops derive makes the eager ones for every changeset at once, and verify --deep then checks the stored values of the built-in derivations against the changesets (§5):

swarmops history main:src/lib.rs --limit 1 --human
find meta/derived -type f | wc -l
swarmops derive
swarmops verify --deep

path: src/lib.rs
entries[0].changeset: 1092352e3a895f0ae9301a5e0637b74ae36763b57d3e907897e0e0408a07830b
…
2
{"ok":true,"op":"derive","api":1,"result":{"derived":15,"cached":0,"next":20},"meta":{"repo":"…","elapsed_ms":1,…}}
{"ok":true,"op":"verify","api":1,"result":{"objects_checked":45,"changesets_checked":15,"problems":[],"findings":[]},"meta":{"repo":"…","elapsed_ms":2,…}}

What it saves#

At the size of the pilot's store, SwarmOps' own 470 commits with a change landed on top, removing meta/derived/ took it from 92 MB in 17,230 files to 57 MB in 8,859 files (measured on 2026-10-20). An export into an empty git directory stored its 8,371 values again and wrote the same head; an export to the branch that already held everything wrote nothing and still stored 2,544 of them. So the values trade room for the time a later export spends deriving them, and the objects, most of a store, stay.