KaTeker Introduction

Topics

Introduction

Backup media

Introduction

The page Backup strategies describes the the ideas and strategies of KaTeker. This page explains how KaTeker works.

KaTeker saves selected files into archives. There are two levels of archives, the master archive and the update archive. The master archive is created by the command master and the update archive by the command update. The master archive contains all files to save while the update contains only those files which are changed since the last master. Master is a full backup while update is a differential backup. The master archive and the update archive can be copied onto save media like CDs. If necessary, files can be restored from the master archive, update archive or any save media (CD).

The master archive can be up to several GB of data. Thus the master archive does not fit onto a single CD. The archive files have to be saved onto several media. Distributing the data onto CDs is supported by KaTeker. The update archive is much smaller and will fit onto a single media.

The master archive is created relatively seldom, once a month or three months. Then the master archive is saved onto save media. The update archive will be created once a day. It should be saved onto save media daily too. That is the update process should run automatically. It is a good idea the save the daily update onto different media. Thus you'll get a lot of media which can hold files. That is, it may be complicated to restore a file. You need information which media or whether the master or update holds the file you want to restore. Therefore KaTeker contains a database with information about the contents of the archives and media.

Another problem is to select the files to be saved. This is supported by KaTeker too. Files or directories including the subdirectories can be selected. On the other side it possible to exclude some files or directories. That is, you'll get a set of directories and files to be saved. Such a set is called a backup set. KaTeker can manages several backup sets. It can be a problem to split the archive into chunks which can be saved onto several media. This process is a lot of work and you need information of the usage of your file system. Splitting archives automatically is supported by KaTeker.

The archives are a set of zipped tar or dar archives. That is the data may be restored if the system crashed. The structure of the archives is described on the page 'the archives'. In the following text we will use "archive" for master or update archives as well as for the tar or dar archives in the backup sets.