majorlinux 91455fac39 Add 7 articles; update nav and existing articles (2026-04-25)

New articles:
- pihole-doh-dot-bypass-defense
- pihole-v6-adlist-management
- mastodon-db-maintenance
- mastodon-federation
- fantastical-google-phantom-calendar-syncselect
- rsync-tailscale-teardown-stall
- ollama-chat-template-pipe-stdin-bypass

Updated: wsl2-backup, wsl2-rebuild, ssh-config-key-management,
selfhosting index, mastodon-instance-tuning, ansible-check-mode,
windows-openssh, windows-sshd, yt-dlp, README, SUMMARY, index
Removed: fedora-usrmerge-ebtables-blocker (superseded by prior push)

2026-04-25 17:52:48 +00:00

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Mastodon DB Maintenance

Mastodon aggressively caches remote content — avatars, statuses, follow graphs — from every instance it federates with. On an active instance, this causes substantial PostgreSQL bloat over time. Without periodic maintenance, the database grows unbounded even if S3 handles media.

The Problem — majortoot at ~3.5 years

Table	Size	Rows
`statuses`	3.5 GB	3.6M rows (3.6M remote cached, 37K local)
`accounts`	499 MB	214,770 remote cached, 18 local
`preview_cards`	837 MB	remote link previews
`statuses_tags`	506 MB	cascades from statuses
`conversations`	436 MB	cascades from statuses
`mentions`	305 MB	cascades from statuses

The statuses remove and accounts cull commands address most of this.

Maintenance Tasks

1. Cache Clear

Clears in-memory Rails caches. Fast (<5 seconds), safe to run anytime.

tootctl cache clear

2. Statuses Remove

Removes cached remote statuses (and their cascaded rows in statuses_tags, mentions, conversations, status_stats) older than N days. Does not touch local statuses.

tootctl statuses remove --days=90

[!warning] This is the slowest step On a 3.6M-row statuses table, the extraction phase alone can take 20–40 minutes. PostgreSQL will be under heavy load. Run during off-peak hours.

What gets removed: Remote statuses not pinned, not boosted by local users, and not replied to by local users, older than the threshold.

3. Accounts Cull

Contacts each remote account's home instance via WebFinger to check if it still exists. Removes accounts that return 404 or Gone. Catches dead instances, deleted accounts, and renamed handles.

tootctl accounts cull

[!note] Network-bound Cull makes HTTP requests to remote servers. It's slower on flaky network conditions and will skip accounts it can't reach (to avoid false deletions).

4. VACUUM ANALYZE

After large deletions, PostgreSQL does not immediately return space to the OS — dead rows sit in pages marked for reuse. VACUUM ANALYZE reclaims that space and updates query planner statistics.

sudo -u postgres psql mastodon_production -c "VACUUM ANALYZE;"

For recovering actual disk space (not just marking pages free), VACUUM FULL is more aggressive but locks tables. Stick with plain VACUUM ANALYZE for routine maintenance.

The Maintenance Script

Location: /home/mastodon/maintenance.sh
Cron: 0 2 * * 0 — Sunday 2 AM (runs before media prune at 3 AM)
Log: /var/log/mastodon/maintenance.log
Notifications: Email to marcus@majorshouse.com at each step via Postfix → MajorMail

The script runs all four tasks in sequence and sends a notification email:

On start — lists steps and current DB size
After cache clear — confirms done, warns statuses remove will take a while
After statuses remove — summary output + current DB size
After accounts cull — accounts removed + current DB size
On completion — full timing breakdown and final DB size

Running Manually

ssh root@100.110.197.17
bash /home/mastodon/maintenance.sh

Monitoring Progress

ssh root@100.110.197.17 "tail -f /var/log/mastodon/maintenance.log"

tootctl Wrapper (one-off commands)

The mastodon user's rbenv is not on PATH in a login shell. Always use the wrapper:

su - mastodon -c 'export PATH="/home/mastodon/.rbenv/bin:/home/mastodon/.rbenv/shims:$PATH" && eval "$(rbenv init -)" && cd /home/mastodon/live && RAILS_ENV=production bin/tootctl <command>'

Full Cron Schedule on majortoot

Time	Job	Script
Sun 2 AM	DB maintenance	`/home/mastodon/maintenance.sh`
Sun 3 AM	Media prune (S3)	`/home/mastodon/media-prune.sh`
Daily 8 AM	Fail2Ban digest	`/usr/local/bin/fail2ban-digest.sh`
Monthly	Fail2Ban nginx-botsearch prune	`/usr/local/bin/f2b-prune.sh`
Daily	Certbot renewal	`service nginx stop; certbot renew; service nginx start`

First Run Results (2026-04-22)

First maintenance run ever on majortoot after ~3.5 years of operation. Results pending (job running in background at time of writing). Check /var/log/mastodon/maintenance.log for final numbers.

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