Backup and snapshot technologies focus on making, managing and storing copies of data as it exists at specific single points in time (i.e., SPIT copies). While faster recovery objectives can be met by making more frequent SPIT copies, doing so is time consuming and expensive. But in the event of a data loss, corruption or a disaster, the recovery point is only as good as the most recent snapshot any data added since the snapshot was taken is lost. And snapshots can be very expensive in terms of disk usage and trained personnel to perform the operations.
Continuous Data Protection (CDP) technology has evolved as a means of allowing instant access to data at variable points in time - thus eliminating the need to make, manage and store SPIT copies. One of the leaders in CDP is Revivio Inc. of Lexington, MA. It offers the Revivio Continuous Protection System (CPS).
When data enters the system, it is simultaneously copied, tagged with the exact time of day, and stored, says Kirby Wadsworth, senior vice president at Revivio. As any changes to that data occur, the new data is stored, but the tags (pointers) to the old information remain in management by the appliance.
Whenever a restoration is required, the user requests a copy as it existed at any prior point in time. This Revivio calls a TimeImage view. It is a mountable, writable virtual volume that can be tested, immediately mounted, copied to restored production servers and storage, copied to a long-term archive and analyzed to determine the causes of failure.
The Revivio appliance is configured by a volume manager (such as Veritas VxVm) as a mirror and as such is provided the identical data stream at the identical time as the primary operations. Using no host-based agents or other intrusive means, its copy-on-write technology creates the mirror (called the CurrentStore) and the indexed group of changes to the data (called the TimeStore). When restoration is required, the user requests a TimeImage view of the data volume as it existed at any point in time just prior to the problem event. It takes only a few moments for the administrator to have the virtual LUNS prepared and available on the wire or a table/file/volume restored.
Industry averages have been quoted as approximately 14 hours to recover a file from tape, and approximately two hours to recover a file from a disk-based archive, says Wadsworth. The former is hampered by the requirement to locate, copy and restore from a manual volume which is often offsite (i.e., tape stored at someplace like Iron Mountain). The latter is hampered by the need to copy the volume to live physical disk space.
The base-model high-availability (HA) version Revivio Continuous Protection System model CPS 1200 costs around $250,000. This is based on a dual redundant (HA) architecture and comes as a turnkey appliance. The customer installs the system and allocates the appropriate mirror volumes on any storage system appropriate to the network. Entry-level systems (non-HA, and with a smaller data footprint) start at under $70,000.
Revivios CPS 1200 includes several integrated elements: The TimeImage Restore Appliance Controller, TimeImage Restore Appliance Manager, TimeImage Array (stores metadata associated with TimeImage volumes), Auxiliary Power Module, Remote Access Module and a Replication Module (for communication between appliances). It provides second-by-second granularity to any point prior to a data loss or corruption incident.
On both the host side and array side, it provides dual 2 Gbps Fibre Channel ports. Supported SAN environments include: host operating systems such as AIX, HP-UX, Sun Solaris, Windows 2000 Server, Windows 2003 Server and Linux; SAN switches by Brocade, McData and QLogic; and management interfaces such as GUI, SMI, CLI and SNMP.
The Remote Access Module adds secure 24-hour monitoring for CPS appliances. It resides within the appliance cabinet, allowing instant access without compromising the network.
The Remote Access Module allows Revivio to leverage existing Internet connections as a means to securely connect to the CPS appliance, says Wadsworth. With its remote diagnostic capability, the system can be monitored and maintenance performed without the need to install dedicated access lines or dispatch a field engineer. This also eliminates the need to open holes in network firewalls typically found within other IP-based remote access methods.
The Remote Access Module is a 1U module, rack mounted within the CPS Appliance cabinet or near the appliance if rack mounted separately. It is hardwired via an Ethernet connection directly to the appliance.
Article courtesy of Enterprise IT Planet