Scenario

Before performing a system-wide database schema migration, you've been asked to ensure that all existing .db files are safely backed up. These files may be scattered across multiple subdirectories, and simply renaming them isn't enough. You must create backup copies with the .db.bak extension, preserving directory structure and permissions.

Task

Recursively scan a given directory (/opt/data/) and create backup copies of all files ending with .db. Each backup should have the same name but with the .bak suffix added (e.g., app.db → app.db.bak) and remain in the same directory as the original file, ensuring the originals are left untouched.

Example

# Before (only original .db files exist)

/opt/data/apps/inventory.db
/opt/data/logs/session.db
/opt/data/config/settings.db

# After (backup copies created alongside originals)

/opt/data/apps/inventory.db
/opt/data/apps/inventory.db.bak
/opt/data/logs/session.db
/opt/data/logs/session.db.bak
/opt/data/config/settings.db
/opt/data/config/settings.db.bak

Step 1: Navigate to the target directory and list all .db files

cd /opt/data/
find . -type f -name "*.db"

The -type f ensures only regular files are found, not directories.

Step 2: Create backup copies with .bak extension

find . -type f -name "*.db" -exec cp {} {}.bak \;

The -exec runs cp for each file found. {} is replaced with each filename, {}.bak appends .bak extension, and \; terminates the command. Using cp instead of mv keeps originals intact.

Step 3: Verify backups by comparing file sizes

find . -type f -name "*.db" -exec sh -c 'ls -lh "$1" "$1.bak"' _ {} \;

Confirms both original and backup files exist with matching sizes.