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Diffstat (limited to 'README.org')
| -rw-r--r-- | README.org | 57 |
1 files changed, 57 insertions, 0 deletions
@@ -21,6 +21,7 @@ manual module loading or package installation during the install process. - *Genesis Snapshot* - Automatic pristine-state snapshot after installation - *Rollback Script* - One-command factory reset via ~/root/rollback-to-genesis~ - *Pre-Pacman Snapshots* - Automatic snapshots before package operations +- *Snapshot Retention* - Automatic pruning keeps disk usage bounded - *GRUB Snapshot Boot* - Boot into any ZFS snapshot directly from GRUB menu - *NetworkManager* - WiFi configuration copied to installed system - *SSH Ready* - Optional SSH with root login for headless servers @@ -94,6 +95,7 @@ archzfs/ │ ├── install-archzfs # Interactive installation script │ ├── install-archzfs.conf.example # Example config for unattended install │ ├── grub-zfs-snap # ZFS snapshot GRUB menu generator +│ ├── zfs-snap-prune # Snapshot retention/pruning script │ ├── 40_zfs_snapshots # GRUB generator script (for /etc/grub.d/) │ └── zz-grub-zfs-snap.hook # Pacman hook for auto-regeneration ├── scripts/ @@ -509,6 +511,61 @@ zpool status zpool list #+END_SRC +** Snapshot Retention Policy + +The system automatically prunes old snapshots to prevent unbounded disk usage. + +*** Retention Rules + +| Rule | Description | +|------+-------------| +| Keep 20 most recent | Always preserved regardless of age | +| Delete if >180 days | Snapshots beyond position 20, older than 6 months | +| Genesis protected | Never deleted, regardless of position or age | + +*** How It Works + +Pruning runs automatically: +- *After every pacman operation* - Pre-pacman hook triggers prune after creating new snapshot +- *Daily via systemd timer* - Catches any missed pruning, syncs GRUB menu + +*** Manual Pruning + +#+BEGIN_SRC bash +# Preview what would be deleted +zfs-snap-prune --dry-run + +# Run with verbose output +zfs-snap-prune --verbose + +# Check current snapshots +zfs-snap-prune --help +#+END_SRC + +*** Customizing Retention + +Set environment variables before running: + +#+BEGIN_SRC bash +# Keep more snapshots (default: 20) +KEEP_COUNT=50 zfs-snap-prune + +# Shorter retention period (default: 180 days) +MAX_AGE_DAYS=90 zfs-snap-prune + +# Different pool/dataset +POOL_NAME=tank ROOT_DATASET=ROOT/arch zfs-snap-prune +#+END_SRC + +To change defaults permanently, edit ~/usr/local/bin/zfs-snap-prune~. + +*** Example: One Year of Use + +With weekly pacman updates (~52/year) plus genesis: +- Total snapshots created: ~53 +- Snapshots kept: ~27 (20 recent + ~6 within 180 days + genesis) +- Snapshots pruned: ~26 (older than 180 days, beyond position 20) + * Keeping Up-to-Date ** Kernel Updates on Installed Systems |