Detailed Information on the LABS System

Backups are organized in volumes.
The size/contents of volumes are determined dynamically to fit the existing storage space.
Volumes are created locally.
In the network mode, they are transfered to storage servers.

Computers to be backed-up are grouped in backup domains.
A backup domain can be as small as one computer (standalone mode) or as big as all the computers of a LAN (network mode).

Each backup domain has one or more storage servers with dedicated disk space for backups.
In the network mode, the storage servers share information and dynamically manage the dedicated disk space for the most efficient use of available resources.
Retrieval of backup volumes and restore requests by the storage servers is done by polling the members of the backup domain.

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The LABS software has two components.

  1. Backup engine:

• splits data in volumes
• decides backup type and frequency
• keeps status and history
• create search and restore requests

  2. Storage servers:

• collect volumes from clients -- locally or over the network
• manage available storage and decide the volumes lifetime
• poll the members of the backup domain
• move the data from/to the members of the backup domain
• search and restore files from volumes
• send hints to the members of the backup domain to help decide backup type and frequency

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There are two pre-defined modes of operation:

• standalone mode (local storage)
• network mode (volumes go to storage servers)

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Default configuration should offer reasonable standalone performance.
Basic configuration parameters:

1. Global parameters:

• mode of operation (default = standalone)
• alarm email address (default = root@localhost)
• backup domain name (default = local)
• minimum lifetime of a volume that will trigger an alarm (default = 2 (full backup cycles))

2. For the backup engine component:

• name of storage server (default = localhost)
• starting directories for volumes (default =/home:/etc:/var/spool:/var/log)
• files to exclude
• by name (grep regexp)
• by size (find -size)
• best full backup cycle (default = 30 (days))
• backup user (default = backup)
• created part of the software install
• should be the same for computers from the same backup domain
• import server ssh key for the backup user (if in network mode)

3. for the storage server component:

• partitions/directories to use for volume storage (default = /mnt/backups)
• closest storage server from the same backup domain (default = none)
• new client list (default = localhost)
• make available server ssh key for the backup user (if in network mode)