The Sync source folder is in e:\mydoc\CalibreLib, destination folder is M:\backup\CalibreLib, where M is the drive letter of an USB disk with label "Emacs";

Giving USB Disk a fixed Drive Letter

Right click "My Compter" -> Manage -> Storage -> Disk Management. Right click the USB drive -> Change Drive Letter and Paths, and modify it to M. You can choose any letter between M~Z. A letter before M is not recommended because it could be occupied by virtual drives or CD-ROMs.

Test shows that other USB disk won't use the drive letter "M". And this USB disk("Emacs") always use "M" no matter which USB port it's plugged in;

Define Sync Configuration in Total Commander

1. Open e:\mydoc\CalibreLib in upper(left) panel in TC, M:\backup\CalibreLib in bottom panel;

2. Shift + F12(Commands -> Synchronize Dirs) to show the Sync window of TC;

3. Check "Asymmetric"(because I want a strict mirror of e:\mydoc\CalibreLib, not a copy. see TC doc for detailed explanation) and "Subdirs";

4. Click the button at the left side of the directory input box and choose "add current directories and settings to list". You can verify this by openning file wincmd.ini in TC's installation dir and you can find:

   [SyncOptions] 
   BooksLib_L=E:\MyDoc\CalibreLib\ 
   BooksLib_R=M:\backup\CalibreLib\ 
   BooksLib_Wcs=*.* 
   BooksLib_Flags=9|61|-9
   

In "Configuration and Switches" -> "ini file Settings" of TC's document file(TOTALCMD.CHM), you can find the explanations about settings above.

Define a hotkey in AutoHotkey Script

1

Use this auto sync script

1. Insert USB disk;

2. Press Win+Alt+s;

3. Sync tool of TC will start comparation automatically;

4. When comparation ends, check the result. If it's OK, press Enter to start Synchronize;

That's it.