SnapRAID and mergerfs config planner

Version 1.1.0

SnapRAID protects a synced set of files; mergerfs presents data disks through one pooled path. Enter your disk mounts and content-file paths to prepare both configurations together. The planner checks their relationships without reading disks, writing configuration files, or running a sync.

Data disks

4 / 42
d1
Data disk 1 capacity unit
d2
Data disk 2 capacity unit
d3
Data disk 3 capacity unit
d4
Data disk 4 capacity unit

Parity disks

1 / 3
parity
Parity disk 1 capacity unit

Content files

2 / 12

Output settings

Mergerfs policy Required
SnapRAID blocksize Required

Keep parity outside the pool

SnapRAID and mergerfs can use the same data mount paths, but they solve different problems. SnapRAID records parity and content metadata for independent disks. mergerfs presents selected branches as one pool. The generated fstab line contains data mounts only, so a parity mount cannot become a storage branch by accident.

LayerRolePlanner inputBoundary
SnapRAIDParity and content metadataData mounts, parity mounts, and content pathsNot a live pooled mount
mergerfsOne path over selected branchesThe ordered data mountsNot parity or backup

What is protected between SnapRAID syncs?

SnapRAID updates its recovery information when you run a sync, rather than maintaining live parity for every write. New or changed files since the last sync are outside that latest synced state. The consequences of a failure depend on what changed, so this isn't a substitute for a separate backup.

That makes the timing of syncs part of the storage decision. A mostly unchanged media collection poses a different problem from a database or virtual machine image being rewritten continuously. Read the SnapRAID FAQ before choosing it for frequently changing data.

Why does SnapRAID need content files?

Content files describe the files and checksums associated with the synced data. They are metadata needed for checking and recovery, not another copy of your documents or media.

Plan their copies on genuinely separate devices according to the SnapRAID requirements. Different directory names do not prove physical separation. The planner can compare paths, but only the real host can tell you whether two paths belong to the same disk.

Choose paths and verify boundaries

Use the mount roots and content locations that exist on the real host. The planner can compare path relationships and capacities, but it cannot know physical disk separation, current mounts, permissions, installed versions, filesystem health, recovery state, or whether the layout is a backup.

  1. Use findmnt and lsblk to confirm mount paths and physical disk boundaries.
  2. Compare the selected blocksize, excludes, and mergerfs policy with the installed manuals. Check whether FUSE permits allow_other.
  3. Review permissions and the backup plan before saving either file under /etc or starting a first sync.

What happens to entered paths?

The calculation stays in this browser. This tool does not save or send entered paths, serialize them into the URL, inspect a SnapRAID daemon, or run host commands. For syntax and option details, compare the result with the SnapRAID manpage and mergerfs QuickStart, then read the site privacy notes.