or mirroring in that these technologies only protect one copy of the data (the most recent). If data becomes corrupted in a way that is not immediately detected, these technologies simply protect the corrupted data with no way to restore an uncorrupted version. Continuous data protection protects against some effects of data corruption by allowing restoration of a previous, uncorrupted version of the data. Transactions that took place between the corrupting event and the restoration are lost, however. They could be recovered through other means, such as journaling. Backup disk size In some situations, continuous data protection requires less space on backup media (usually disk) than traditional backup. Most continuous data protection solutions save byte or block-level differences rather than file-level differences. This means that if one byte of a 100 GB file is modified, only the changed byte or block is backed up. Traditional incremental and differential backups make copies of entire files; however starting around 2013 enterprise client-server backup applications have implemented a capability for block-level incremental backup, designed for large files such as databases. Risks and disadvantages When real-time edits—especially in multimedia and CAD design environments—are backed up offsite over the upstream channel of the installation's broadband network, network bandwidth throttling may be needed to reduce the impact of true CDP. An alternative approach is to back up to a separate Fibre-Channel-connected SAN appliance. See also Quest AppAssure Cofio Software Disaster recovery EMC RecoverPoint FalconStor InMage DR-Scout List of backup software List of online backup services Single instance storage CloudEndure References Computer data Backup