speed optimizations

internal/bsdaily/copy.go

@@ -7,6 +7,8 @@ import (
 	"os"
 )
 
+const copyBufferSize = 4 * 1024 * 1024 // 4MB buffer for large file copies
+
 func CopyFile(src, dst string) (err error) {
 	slog.Info("copying file", "src", src, "dst", dst)
 
@@ -31,7 +33,9 @@ func CopyFile(src, dst string) (err error) {
 		}
 	}()
 
-	written, err := io.Copy(dstFile, srcFile)
+	// Use a larger buffer for better performance with large database files
+	buf := make([]byte, copyBufferSize)
+	written, err := io.CopyBuffer(dstFile, srcFile, buf)
 	if err != nil {
 		return fmt.Errorf("copying data: %w", err)
 	}