使用相同版本Unison却生成不同归档文件的问题求助

算力阿峰

2026-5-28

Fixing Unison 2.40.63 "New archives are not identical" Fatal Error

I’ve run into this exact error with Unison 2.40.63 across Windows and RHEL before—super frustrating when everything seems configured right! Here are the solutions that worked for me:

1. Delete Existing Unison Archive Files

Unison stores sync state archives to track what’s been synced. Corrupted or mismatched archives on either system are the most common cause of this error.

On Windows: Navigate to %USERPROFILE%\.unison and delete any archive files matching your sync profile name (e.g., my_sync_profile.archive).
On RHEL: Go to ~/.unison and remove the corresponding .archive files for your profile.

After deleting these, run Unison again—it’ll regenerate fresh, matching archives from scratch.

2. Verify System Time Sync

Unison relies heavily on file timestamps to determine sync state. A significant time difference between your Windows and RHEL systems can throw off archive generation:

On RHEL: Ensure NTP is enabled and syncing with a reliable time server (use timedatectl status to check, timedatectl set-ntp true to enable if needed).
On Windows: Go to Settings > Time & Language > Date & Time and make sure "Set time automatically" is turned on.

3. Check Directory/File Permissions

Mismatched or insufficient permissions can cause Unison to generate inconsistent archives:

On RHEL: Make sure the user running Unison has read/write access to the sync directory and all files within it (use chmod/chown if needed).
On Windows: Right-click your sync folder, go to Properties > Security, and ensure your user account has "Full Control" permissions.

4. Run Unison with `-ignoretimes` Temporarily

If the above steps don’t work, bypass timestamp checks entirely by running Unison with the -ignoretimes flag, which forces it to compare file content hashes instead: