Today, more companies than ever recognize the value and convenience of using online bakup to protect their server data. For any enterprise considering Iron Mountain's LiveVault® solution - or any other online backup service - ensuring the integrity of data both during backup and restore transmission operations, as well as on data stored for longer retentions, is critical to guarantee tht you can recover your data when disaster strikes. LiveVault, which offers on-disk retention for up to seven years, ensures that data under protection is error-free during backup, transmission, storage, and restoration.
For ongoing backups and restores, data integrity checks take place on all packets of data sent between protected servers, vaults, and Turbo Restore Appliances, because LiveVault uses the Secure Sockets Layer (SSL) protocol on top of TCP/IP. These checks ensure that any alterations, additions, or deletions of data during transmission— either accidental or malicious—are detected and corrected by re-transmitting the data. In addition, LiveVault transmits the file ID and block number information redundantly, and validates that the data blocks arrive in the expected order, without gaps, and that the header information is consistent.
When messages arrive at the vault, they are written to disk. The LiveVault vaulting software does no processing on the backed-up data. It arrives compressed and encrypted, and is stored this way. LiveVault vaulting software executes on standard Windows® 2003 servers with RAID 5 disk systems, and the software uses standard Microsoft file system I/O. Source server applications, such as SQL Server® and Exchange, also rely on the integrity of the Microsoft file system.
Unlike most applications, LiveVault takes special steps to validate the integrity of the data on disk. LiveVault vaults employ proprietary technology to index, catalog, and organize the data blocks. This technology enables LiveVault to run four types of consistency checks:
In addition, the "rotation" software helps ensure the integrity of data at rest. As time passes, various backup versions reach the expiration of their retention periods, but some of the data blocks—the ones that have been static—are still needed and are "moved forward" into a new baseline by the rotation software. This process involves copying the blocks, and provides an additional check that disk blocks are accessible, and that the header information is correct. Unlike tapes, which age on a shelf until you attempt a restore, with LiveVault, data is read and rewritten throughout its retention period, thus regularly testing the integrity of the storage systems and software.
For high availability, LiveVault maintains all backup data on two independent vaults at separate geographic locations. Backup data that arrives at the primary vault is then sent to the secondary vault where it is revalidated and stored in the same manner as on the primary vault. If there should ever be an unrecoverable error on one of the vaults, the other vault provides continuity of ongoing backups and the ability to restore historical versions. The vaults continuously cross-check with each other to ensure that each has the same set of backup versions, and they cross-replicate between each other as necessary. When a vault comes back online after repair, it automatically acquires data that it is missing from the other vault.