btrfs balance tips — authorized Btrfs balance literacy

Snapshot

Tip checklist (authorized only)

1. Confirm you may run btrfs balance on the lab host (syllabus box you own; balance needs root and can be I/O-heavy).
2. Prefer documenting who / why / ticket before any balance — never balance production mounts without change control.
3. Record short factual notes; quote short Evidence (mount + filter/status — never secrets).
4. Optional: subvolume peer → btrfs-subvolume-tips.
5. Optional: scrub peer → btrfs-scrub-tips for integrity drills.
6. Prefer disposable lab VMs and throwaway loop-backed Btrfs (losetup-tips, mkfs-tips) for balance drills; quote non-secret labels afterward as Evidence.
7. Prefer btrfs balance status read-back — refuse unauthorized foreign-mount cookbooks.
8. Stop at literacy — no attack or unauthorized disk-bypass cookbooks.

Allowed framing

• Classroom labs reviewing btrfs balance start -dusage=50 /mnt/labbtrfs on disposable mounts.
• Binding short factual notes as Evidence (mount + filter labels — no secrets).
• Documenting expected vs observed balance status for authorized notes.
• Comparing btrfs balance ↔ subvolume / scrub / mkfs / df peer tip pages under one binder.
• Testing syllabus-approved lab-Btrfs balance only when change control authorizes that drill on lab resources.

Scope we will not cover

• No crack/pirate/keygen via btrfs balance.
• No intentional unauthorized balance against foreign mounts.
• No secret-theft or credential harvesting against hosts you do not own.
• No cookbooks that use btrfs balance as an attack step against production without authorization.
• No btrfs balance framed as a disk-bypass against systems you do not own.

Beginner path (authorized only)

1. Obtain one syllabus-approved disposable lab host with btrfs-progs available.
2. Prefer a throwaway loop device with a lab Btrfs filesystem (mkfs-tips, losetup-tips).
3. With authorization, run a filtered btrfs balance start and btrfs balance status; quote selected labels as Evidence.
4. Optional: peer tip pages above when the syllabus asks.
5. Stop at literacy — no attack or unauthorized disk-bypass cookbooks.

Practical notes for authorized labs

• btrfs balance relocates chunks — keep Evidence labels distinct from btrfs-scrub-tips (balance ≠ integrity scrub).
• Pair with df-disk-tips when the syllabus zooms on free-space after balance.
• btrfs balance status is a great read-back drill — document selected filters without dumping unrelated privileged state.
• Prefer documenting mount paths and filter labels the syllabus authorized.
• Never commit balance dumps with secrets or proprietary disk serials to git — even for labs.

FAQ-aligned refusals (quick)

• Foreign-mount balance → refuse.
• Unauthorized disk-bypass / hostile-balance attack cookbooks → refuse.
• Attack/credential-theft framing → refuse.

For legal, authorized and educational use only.

FAQ

Sources