Julien LutranandClaude Fable 5
c18c8edc5b
backup-strategy.md: the two-tool architecture (incus copy + restic), ASCII map of the legs (ks4 sdb / nuc pull / two S3 buckets), the schedule table, a 30-second health check, and restore recipes for a file, a database and a whole instance. new-container.md: conventions for adding a service — one container per service, no Docker (incus runs OCI natively, incus-compose for stacks), gateway/proxy ingress, leave the snapshot schedule alone, what the backups pick up automatically vs the one line to add to restic-paths, DB-discovery requirements (incl. the .my.cnf trap), a verification run, and the pitfalls (tmpfs /tmp, tiny-file swarms, cron PATH). README: start-here links, ks4 durability bullet and flow chart updated to the restic era. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
99 lines
5.8 KiB
Markdown
99 lines
5.8 KiB
Markdown
# ks4 backup strategy (2026-08)
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Audience: anyone with root on ks4 who needs to know **what is protected,
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where, by which tool, and how to check it**. Details live in the linked
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docs; this page is the map.
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## Two tools, no more
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| tool | job | why this one |
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| **`incus copy --refresh`** | replicate whole instances (ready-to-start copies) | ZFS-incremental, native to the platform, restores are `incus start` |
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| **restic** | off-site backups to S3 (files, database dumps, instance trees) | dedup + encryption, local metadata cache → a night costs only the churn ([restic-backup.md](ks4/restic-backup.md)) |
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plakar was evaluated first and replaced (its nightly cost scaled with
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tree size — [PlakarKorp/plakar#2338](https://github.com/PlakarKorp/plakar/issues/2338));
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the old backup server **ks2 is retired** ([ks2/plan.md](ks2/plan.md)).
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## The map
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```
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ks4 (OVH) off-site
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┌─────────────────────────────────────────────┐
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│ live instances pool `data` (sda) │
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│ nextcloud, seafile, mail, git, ... │
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│ │ │
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│ │ 01:00 incus copy --refresh │ nuc (home LAN, via WireGuard)
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│ ▼ │ ┌──────────────────────────┐
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│ replicas (stopped) pool `backup` (sdb) │─────▶│ 05:00 incus copy (pull) │
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│ project `backup` │ │ pool `ks4backup` (USB) │
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│ │ │ └──────────────────────────┘
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│ │ 01:00+ restic (via incus file mount)
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│ ▼ │ OVH Object Storage (S3, sbg)
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│ ───────────────────────────────────────── │ ┌──────────────────────────┐
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│ 05:00 restic-backup.sh │─────▶│ bucket restic-data │
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│ • DB dumps (MariaDB/PostgreSQL, auto) │ │ dumps + all data trees │
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│ • data trees from /root/scripts/restic-paths │ │
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│ 01:00+ restic-incus-backup.sh │─────▶│ bucket restic-incus │
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│ • every replica, per file + config yaml │ │ instance filesystems │
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│ Sun 14:00 restic-maintenance.sh │ └──────────────────────────┘
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│ • prune + check (rotating full verify) │
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└─────────────────────────────────────────────┘
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```
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Copies of any given byte: live → sdb replica (same box, other disk)
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→ nuc replica (other site) → S3 (other site, other technology).
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Databases additionally get application-consistent dumps nightly.
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## Schedule (root crontab on ks4)
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| when | what | log |
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| 01:00 daily | `incus-copy.sh -p backup -s backup` — refresh all replicas onto sdb, then `restic-incus-backup.sh` → S3 | `/var/log/incus-copy.log`, `/var/log/restic-incus.log` |
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| 03:00 daily | instance snapshots (incus profile, 7-day expiry) — what keeps the refreshes incremental | `incus info <inst>` |
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| 05:00 daily | `restic-backup.sh` — dumps + data trees → S3 | `/var/log/restic-backup.log` |
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| 05:00 daily (nuc) | nuc pulls all replicas over WireGuard | nuc: `/var/log/incus-copy-ks4.log` |
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| Sun 14:00 | `restic-maintenance.sh` — prune (capped), structure check, 1/52 data verification | `/var/log/restic-maintenance.log` |
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| 1st of month 06:00 / quarterly 15th | seafile GC dry-run report / real GC ([ks4/seafile-gc.md](ks4/seafile-gc.md)) | `/var/log/seafile-gc.log` |
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Retention on S3: 14 daily, 8 weekly, 6 monthly snapshots.
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## "Did last night work?" — the 30-second check
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```sh
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grep -aE "done \(rc=|FAILED" /var/log/incus-copy.log | tail -2
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grep -aE "snapshot .* saved|done \(rc=|failed" /var/log/restic-backup.log | tail -3
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grep -aE "done \(rc=|failed" /var/log/restic-incus.log | tail -2
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```
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`rc=0` everywhere = fine. Any `failed`/`FAILED` line names the culprit
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(instance, database or path). All scripts exit non-zero on any error,
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never silently.
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## Restoring
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- **A whole instance, fast (same box)**: `incus copy backup:<inst>`
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style — copy the replica from project `backup` back into `default`
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([ks4/incus-copy.md](ks4/incus-copy.md)); from nuc the same via the
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remote.
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- **A file or directory** (any date within retention):
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`restic -r s3:s3.sbg.io.cloud.ovh.net/restic-data restore <snapshot> --target /backup/restore-x --include <path>`
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(never restore into `/tmp` — it is RAM). Env: `. /root/.restic-env`.
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- **A database**: restore the `.sql` dump from `restic-data`
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(`/backup/dumps/mariadb/<inst>/<db>.sql`, `grants.sql` for users), load
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it with `incus exec <inst> -- mariadb < dump.sql`.
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- **An instance from S3 only** (ks4 and both replica sites gone):
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restore its tree + `<inst>.yaml` from `restic-incus`, recreate the
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instance from the yaml/profile, push the tree back.
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Secrets you need for any of this: `/root/.restic-passphrase` and the S3
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keys in `/root/.restic-env` — **both are in the password manager**;
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without the passphrase the S3 buckets are unreadable.
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## Adding something to the backups
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New instances are picked up automatically by the replica and
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instance legs (all instances, opt-out only). Databases are
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auto-discovered. Only **data trees** need one line in
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`/root/scripts/restic-paths` — see [new-container.md](new-container.md).
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