Table of Contents
Backup
The need for backup on campus is very high, especially since department-wide backup service is a non-trivial service for many departments to implement.
Because of the need for a backup system, the Computer Science department has implemented the Free/Open-Source backup system called Bacula. The Bacula system has an impressive feature set and is very flexible for backups across multiple platforms. The current Bacula system doesn't support
- MacOS
Things Bacula can do
Bacula can make backups of the files on your system on a regular basis. These backups can allow you to recover files should be become corrupted or missing due to a critical system failure. Note that due to various circumstances, some files/folders are excluded from being backed up.
Things Bacula cannot do
Bacula is not a file versioning or management system. It cannot stop you from making changes to files you don't want to make, or accidentally deleting files. Even with a backup system in place, caution should still be exercised when working with important and critical files.
Bacula also cannot make you toast in the morning.
Backup Policies
This is the boring part that every user needs to read at least once so that everyone is on the same page about how the system works and why a file deleted 2 years ago cannot be retrieved.
File Backup Method
Bacula utilizes a client-server architecture in which the backup server requests that a given client perform a backup. The client then determines which files to back up and those are sent to the server. The server happily stores and manages these files.
A full backup will be performed and then incremental backups will occur on a daily basis. Periodically the backup server will consolidate many of your backups into a new Full backup. This is described in detail below.
Backup Security
Files are encrypted on the client before being sent to the server. This ensures that anyone that may be intercepting the communication cannot read the files. This also ensures that (should the backup server be compromised) no files could be read by anyone who physically obtains the hard drives. The encryption keys are generated when the client installer is requested from the CS Dept Bacula download page. These keys are then placed on your hard drive when the client is installed. For someone to obtain your data through the backup system they would need to obtain these keys first, meaning an attacker would already have the data as it would be on the hard drive to begin with.
Files To Be Backed Up
By default, your C:/ drive is backed up with some exceptions. If you would like other drives backed up you MUST contact the backup administrator with a request to add more drives.
What is NOT backed up
Certain system folders and files are excluded for various purposes. Sometimes they are not needed to restore data (like browser cache), they may be files we do not back up, or they may be excluded to conserve space on the server.
The following files and folders are NOT included in backups
| File/Folder Name | Reasoning |
|---|---|
| Any 'Program Files' directory | Many programs need to be completely installed and can be reinstalled if required |
| Windows system directories | Should these become missing or corrupt, a reinstall is often required, some of these take up large amounts of space |
| Recycle bins | These are not necessary |
| Page file/hibernation file | Not necessary |
| Temporary files (*.temp, *.tmp) | These are almost always files left by an installer |
| Cookies, web browser cache folders | Not necessary |
| Any folder named 'Temp' | These typically contain files that are temporary and not necessary |
| System user directories (Default User, LocalService, NetworkService, sysadmin) | These should not contain user files |
| Any folder named 'backups' | The backup system should not be backing up existing backups |
| Virtual Machines (*.vdi, *.vmc, *.vmdk, *.vmem) | These are omitted to conserve space on the server |
| iTunes directories | Personal music stored on your computer should be backed up separately and will not be backed up |
| Directories containing a file named '.bexclude' | The backup system is designed to exclude ANY directory (and all files/subdirectories within) if the directory contains a file called 'bexclude'. |
'Windows system directories' includes: c:\Windows, c:\MSOCache, c:\i386, c:\RECYCLER, and other similar directories.
How to explicitly exclude a directory on your computer
If you have a directory you would explicity NOT want backed up, you can simply create an empty file named 'bexclude' and put it in that folder. The backup system will ignore any directory (and all subdirectories within) that contains one of these files.
What IS backed up
Every other file and folder on your C:\ drive is backed up, this includes your Desktop, Documents, Pictures, Email and anything else not excluded above.
If you would like another drive backed up, contact the backup administrator.
Backup rotation and retention periods
Backup retention period
At any time, you will have access to AT LEAST one weeks worth of backups. The server may have more than that, but there is no guarantee of having backups older than one week. Based on your client's usage of server space, you may have have access to more than one week. Clients using less space may be allowed to have backups reaching as far back as a month or longer.
Detail of backup retention methods
Initially a full backup is performed on a given computer. After this full backup, incremental backups occur on a daily basis until such time that the server needs to reclaim some of its drive space. The server will then select the client using the most space, consolidate their backups into a new 'full' backup (or perform a new full backup) and then after one week has passed, remove all backups for that client which are older than one week.
This ensures that a full week is stored while minimizing space used on the server. This scheme also allows for more flexibility and the possibility of long retention periods for certain clients.
Restoring files
File restoration through the console is detailed here but probably no longer works. Ask the System Admin for an archive file of your backed up information.