147 lines
6.4 KiB
Markdown
147 lines
6.4 KiB
Markdown
# seafile: garbage collection + history retention
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Status: **GC executed 2026-08-26/27.** Results:
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| metric | before | after |
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|---|---|---|
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| dataset inodes | 24,885,504 | **515,842** (after Documents recreation + final `-r`, 2026-08-28) |
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| `storage/blocks/` | 867 G | **632 G** (−235 G) |
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| fs objects | ~19.3 M | ~100 k (19,207,400 removed) |
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| ghost library stores | 13 | 0 (blocks/fs eaten by GC; 4 empty commit husks removed manually — `--rm-deleted` couldn't see them, they predate `GarbageRepos`) |
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| wall time | | 16 min (blocks) + 0.2 s (`-r`) + **21 h 33 m** (`-R`) |
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**Root-root-cause found**: one library — Documents
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(`c4ec7247`, 2.9 G data) — held **19.02 M fs objects and ~4.9 M
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commits**: a client has been committing at extreme frequency for
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years. The ~4.9 M commit objects survive GC (CE never deletes commit
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objects) and are most of the remaining inodes. Remedy: identify and
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fix the committing client, then **recreate the library** (sync down
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current state → new library → delete old → GC `-r`, which works for
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12.x-era deletions) — that retires the commit store entirely and
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takes the dataset to ~600 k inodes, at which point per-file backup of
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seafile becomes ordinary.
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All crontab backup jobs on ks4 remain commented out until restart +
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validation completes.
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## Root cause of the 24.9 M-inode / 933 G dataset
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Investigated after per-file backups of `/opt/seafile` proved
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unwalkable (restic seed: ~20 M objects remaining at ~66 files/s).
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Findings (seafile-server **12.0.14**, binary install, upgraded from
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8.0 → 9.0 → 12.0):
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- **GC has never run** — no `gc.log` ever, no cron in the container.
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`seaf-gc` is the *only* mechanism that deletes blocks/fs/commits
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objects; without it nothing is ever reclaimed.
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- **13 ghost libraries**: `storage/commits/` holds 30 library dirs;
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the DB has 17 live repos and an empty trash. Deleted libraries'
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object stores persist until `seaf-gc --rm-deleted`.
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- **Unlimited history on 16 of 17 repos**: only one library (the
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240 G one) has a retention limit (30 days, `RepoHistoryLimit`).
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Everything else keeps every version of every file since creation.
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- Sizes: live repo data ≈ 710 G (DB `RepoSize`) vs **867 G** in
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`blocks/` → ≥150 G dead blocks; the rest of the dataset is the
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fs/commits object swarm (~5 M commits objects counted; fs likely
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15 M+, sub-4K each) — the thing that makes every per-file walk
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take days.
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References: <https://manual.seafile.com/12.0/maintain/seafile_gc/>
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## Procedure
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### 0. Safety net (host, instant)
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```sh
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zfs snapshot data/containers/seafile@pre-gc # rollbackable; delete after validation
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```
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Leg-1 replica on sdb is the second net (crontab currently disabled —
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the replica is pre-GC state, which is exactly what we want here).
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### 1. Default history retention (inside the container)
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`/opt/seafile/conf/seafile.conf`:
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```ini
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[history]
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keep_days = 90
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```
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Applies as the default for all libraries without a per-library
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setting (the existing per-library 30 d row stays). Users can still
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override per library in the web UI if
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`ENABLE_REPO_HISTORY_SETTING = True` in `seahub_settings.py`.
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### 2. GC — offline, maintenance window
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CE's GC requires seafile stopped. On this pathological store expect
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**hours** (it traverses fs/commits on a cold HDD); the dry-run sizes
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the window. Inside the container:
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```sh
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cd /opt/seafile/seafile-server-latest
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./seahub.sh stop && ./seafile.sh stop # or the container's systemd units — check systemctl
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./seaf-gc.sh --dry-run # per-repo report of what would be reclaimed
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./seaf-gc.sh # blocks GC, honors keep_days
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./seaf-gc.sh --rm-deleted # purge the 13 ghost libraries
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./seaf-gc.sh --rm-fs # unreferenced fs objects — the inode bulk
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# (verify flag names: ./seaf-gc.sh --help; manual 12.0)
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./seafile.sh start && ./seahub.sh start
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```
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### 3. Measure the result (host)
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```sh
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df -i /var/lib/incus/storage-pools/data/containers/seafile # was 24,885,504 inodes
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du -sh .../seafile/rootfs/opt/seafile/seafile-data/storage/blocks # was 867 G
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```
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### 4. Aftermath
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- validate seafile works (client sync, web, download a versioned
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file), then `zfs destroy data/containers/seafile@pre-gc`
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- re-enable the crontab (incus-copy leg first; its next refresh
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transfers the shrunken dataset)
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- **recurring GC** (done 2026-08-27 design): the MySQL backend runs
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GC *online* (verified — the runs printed "use online GC" and `-r`
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ran with services up), so no stop/start is needed. Host crontab:
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```cron
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# monthly dry-run report (cheap health check, read-only)
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0 6 1 * * incus exec seafile -- sh -c "cd /opt/seafile/seafile-server-latest && ./seaf-gc.sh -D" >> /var/log/seafile-gc.log 2>&1
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# quarterly real GC: blocks + trashed repos + fs objects
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0 6 15 1,4,7,10 * incus exec seafile -- sh -c "cd /opt/seafile/seafile-server-latest && ./seaf-gc.sh && ./seaf-gc.sh -r && ./seaf-gc.sh -R" >> /var/log/seafile-gc.log 2>&1
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```
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At the post-cleanup scale (~120 k live files) the full sequence is
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minutes, not hours. Keep it clear of the 01:00/04:30/05:00 backup
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slots.
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- 2026-08-27 follow-ups executed: 8 old libraries deleted by user →
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trash emptied → `seaf-gc -r` purged their stores (18 m, blocks now
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590 G, −277 G total); 4 pre-`GarbageRepos` husks removed manually;
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Documents to be recreated from a local re-sync (retires its ~4.9 M
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fossil commit objects → expected final ~600 k inodes)
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- re-decide seafile's S3 backup with real post-GC numbers:
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per-file restic redux if the object count collapses far enough,
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`zfs send | restic --stdin-from-command` otherwise
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(see [restic-backup.md](restic-backup.md))
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- then plan the 13.x upgrade (Docker-only — see the incus-compose
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notes and
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<https://manual.seafile.com/13.0/upgrade/upgrade_notes_for_13.0.x/>)
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against a much smaller estate
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## Related cleanup while in there
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- `logs/seafevents.log.2024-*` and friends — years of rotated logs
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- the old `seafile-server-8.0.7` / `9.0.10` dirs once 12.x is proven
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## Closure (2026-08-28)
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Documents recreated from a local re-sync, old library trashed → trash
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emptied → `seaf-gc.sh -r` (78 m) retired its ~4.9 M fossil commit
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objects. **Final: 515,842 inodes (from 24,885,504, −98 %), blocks
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590 G (from 867 G), 8 libraries / ~120 k live files / 703 GB.** The
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`@pre-gc` snapshot can be destroyed once the new Documents library has
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proven itself for a few days (it pins the freed space until then).
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