While backing up to a local computer is pretty straightforward, trying to accomplish the same thing over a network is often raising some difficulties with the hardware and software involved. Having played around with various USB-storage capable routers, shared directories, mounted network drives and log-on scripts, I have finally arrived at a simple and reliable solution using Apple’s Time Capsule.
This article assumes that you are using the following:
Setting up the Time Capsule
Configuring the Time Capsule is very easy using the AirPort Utility and consists of just two steps: enabling file sharing and adding an user account.
- Start the AirPort Utility and connect to your Time Capsule
- Select the Disks page
- Select the File Sharing tab
- Check the Enable file sharing box
- Set the Secure Shared Disks option to With accounts
- Click the Configure accounts… button
- Add an account Backup with your desired password and give it read/write access
- Click Ok, then Update to restart the Time Capsule.
Adding the Backup user account creates a shared folder called Backup in the root of your Time Capsule where the Data directory resides as well.
In order to avoid complicated scripts and network mappings, we add a special Windows user account that performs the actual backup jobs. This user will be used :
- Open the Control Panel, go to Administrative Tools and start Computer Management
- Select the Local Users and Groups node
- Click the Action main menu item and select New User…
- Configure and create a new user Backup with the same password as in the Time Capsule.
To avoid issues with file access permission during backups, add the Backup user to the Backup Operators user group. This will give the backup service the necessary read access to all files on your computer, including those that are protected by custom folder permissions.
Since the Backup user is only intended to be used for the backup software, it should be hidden from the Windows log-on screen. The following steps apply to XP, Vista and Server versions of Windows:
- Open the registry editor (Start Menu → Run… → regedit)
- Navigate to the key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\Winlogon\SpecialAccounts\UserList
- Add a new DWORD value named Backup and leave the default value of 0×00000000.
Configuring Cobian Backup
Getting Cobian Backup up and running consists of two more steps: setting up the Cobian Backup service to use the Backup account and configuring the target directory for your backup in the backup task options.
The following assumes that you run Cobian Backup as a system service. If you run it as an application, you should reinstall the program as a service.
- Open the Control Panel, go to Administrative Tools, and start Computer Management
- Select the Services node
- Right-click the Cobian Backup 9 service and select Properties
- Select the Log On tab
- Enter the Backup account and corresponding password, and click Ok.
You can edit your backup task in Cobian Backup to point to the correct target directory on the Time Capsule. My Time Capsule is called Time-Capsule, so the path to the directory is: \Time-Capsule\Backup\
Note on Personal Folders
If simple file sharing is disabled, personal folders, such as Favorites and My Documents are private by default. Unless explicitly added to the directories’ security permissions, neither the Backup Operator nor Administrator accounts have access to them.
If you wish to backup any of those folders, you have to give the Backup account permission for read access. In addition to that, if you use the File Attribute Logic in Cobian Backup, you also have to allow write access to file attributes. In Windows XP and later this can be done on the file’s or folder’s Special Permissions dialog by clicking the Advanced button on the Security properties page.
If you already have backup files in another directory on your Time Capsule, and you did not use User Accounts before, your old backup files will likely no longer be accessible using the new Backup user account. By temporarily switching the Time Capsule access control back to Time Capsule Password on the AirPort Utility’s File Sharing tab, it is possible to copy the old files into the Backup directory.
On Mac computers, the Backup directory can be made permanently accessible to backup programs, such as SmartBackup by clicking on the Time Capsule in the Finder, selecting Connect As… with the Backup user name and password and saving the password in the key chain.