(IDR=Intelligent Disaster Recovery ) System Disaster Recovery is the ability to rebuild a system, including the system patches, applications and data on it, in very few steps in the event of a system crash. This improves recovery accuracy, shortens recovery time, and reduces business interruption.
The main disaster recovery technologies, there are several ways to recover:
The use of a common CD-ROM, which is used for all systems. This CD-ROM boots the system and boots the network at the same time, and then the backup server restores the entire contents of the hard disk or the first primary partition backed up in the tape library (or virtual tape library) to the disaster machine. In this way, no matter how large the original capacity of the disaster machine data, can be stored in the backup device of the entire backup system, unified management, and do not need to burn the CD-ROM, that is to say, the CD-ROM does not need to be updated frequently. A typical representative is BakBone NetVault VaultDR. The figure on the right shows the data flow of BakBone NetVault VaultDR disaster backup and recovery, which is carried out by a unified CD-ROM for all systems.
Individual CDs need to be burned for each computer, and recovery needs to utilize targeted CDs for recovery, with each machine needing its own CD-ROM that needs to be kept up to date on a regular basis. The biggest shortcoming of this approach is that it is often necessary to carve CD-ROMs, otherwise, when a disaster occurs, if there is no CD-ROM or the CD-ROM is too long, it will affect the speed of recovery and the state of the recovered state. This technology is typified by the EMC NetWork Recovery Manager module.
Recovery requires a network boot, which means that you need to have a host with the same operating system as the boot machine, and then utilize the contents of the backup for recovery. This technology is typified by Symantec NetBackup's Bare Metal Restore module.
Disaster recovery tools provided by the operating system itself. For most Unix minicomputers, a system backup tool is provided. With the help of the tape drive provided by the system itself, using a simple command, HP-UX using make_recovery can back up the entire root volume to the 4mm tape that comes with the server. At the time of recovery, this tape can self-start the system, using a single command to restore the entire root volume to the hard disk. The benefits of this approach are simplicity and economy, especially for Unix systems, and it is far more convenient, secure, and economical than backup software-provided BMR modules, which often require other servers on the same platform to boot. The data will be in another place in real time to produce a usable copy, this copy of the use of data recovery does not need to do, you can put the copy immediately into use. The biggest benefit of data replication is that the copy data is immediately available, there is no data recovery time, the RTO is very good, and also because it is a real-time replication, the RPO is also very good, there is almost no data loss. The disadvantage is that the cost is much higher than the data backup, not only is the price of the data replication system is high, but also need another hard disk storage space and host system, and even set up another remote server room, consider the network cabling, all of these will bring the cost greatly increased, so the construction and maintenance costs of data replication is much greater than the data backup.
Data replication is currently implemented in the following ways:
Host-based. Host-based data replication technology, you can not consider the storage system isomorphism, as long as the host is to maintain the same operating system can be, there is support for heterogeneous hosts between the data replication software, such as BakBone NetVault Replicator can support heterogeneous servers between the data replication can be supported to support across the wide-area network of remote real-time replication. The disadvantage is that it takes up a bit of host resources.
Based on the storage system. Utilizing the data replication software provided by the storage system, the replicated data streams are passed between storage systems, independent of the host. The advantage of this approach is that the data replication does not take up host resources, the disadvantage is the need for disaster recovery center storage system and production center storage system has strict compatibility requirements, generally need to come from the same manufacturer's storage system, which brings limitations on the user's disaster recovery center storage system selection.
Based on fiber optic switches. This technology is under development, the use of fiber optic switch new features, or the use of management software to control the fiber optic switch, virtualization of the storage system, and then management software on the management of the virtual storage pool of volume management, volume replication, volume mirroring and other technologies to achieve the remote replication of data. More typical Storag-age, Falcon and so on.
Application-based data replication. This technology has certain limitations, are application-specific. The main use of the database itself to provide the replication module to complete, such as OracleDataGuard, Sybase Replication and so on. CDP (Continuous Data Protection)
CDP technology is currently the hottest data protection technology, which can capture all file-level or data block-level data write changes can be made to the backup object for a more granular granularity of the recovery can be restored to any point in time.
CDP technology is an emerging technology that is gradually being incorporated into many traditional backup software. For example, BakBone NetVault Backup 8.0 added TrueCDP module, Symantec Backup Exec12.5 and so on. Other companies, including EMC, Symantec have acquired some CDP software, and traditional backup software integration, are still in the integration.
CDP technology includes two kinds:
Near CDP, that is, we say quasi-CDP, its biggest feature is that it can only restore part of the specified point in time data (FPIT, Fixed Point In Time), somewhat similar to the storage system's logical snapshots, which can not be restored to any one point in time. Such as Symantec, CommVault, Kai Backup's CDP all belong to this type.
TrueCDP, we call it true CDP, it can recover any point in time within the specified time period (APIT, Any Point In Time), and BakBone TrueCDP belongs to the TrueCDP type. If the use of disaster recovery programs are distributed in various industries, but everyone uses them according to a certain gradient.
The first one used is the system disaster backup (BMR Bare Metal Recovery), because this solution has the lowest cost, as long as in the construction of the data backup system can be completed with some additional modules. There is no need for additional storage space or an additional disaster recovery server room, so almost all users who are in a position to do so can implement it. Only some users use the backup tool provided by the operating system to assist, and some users use the disaster module provided by the backup software to complete. Such users are the largest in number and are spread across a wide range of industries.BakBone's VaultDR is widely adopted among backup software users using BakBone NetVault. Many users like the fact that BakBone VaultDR doesn't have to care about operating system type and that one standard CD can be applied to all Intel x86 servers for disaster backup and recovery.
Secondly, for those who are setting up disaster recovery systems, storage-based data replication is commonly used by high-end enterprises with large data volumes, such as the telecom and financial industries. Middle and low-end users generally use host-based data replication software, the cost is low, and do not need to carry out harsh storage system procurement, especially BakBone's NetVault Replicator can not only carry out remote data replication, but also support heterogeneous platforms, so there are a wide range of users at home and abroad, a number of government departments, electric utility companies, securities departments, website companies Some government departments, electric power companies, securities departments, website companies, etc. have adopted this approach, and most of them are used in Windows and Linux platforms. Although the virtual storage technology based on the storage switch layer also has a number of users, but because of the limited start time of this technology, the maturity of the technology needs to be further verified, a lot of users are just doing as a pilot, there is no wide-scale development. For application-based data replication, there are some high-end customers in the adoption, and there are also a large number of users.
For CDP technology, just started, this technology meets the needs of many users concerned about disaster recovery, in the RTO and RPO can get a high standard, but also can be reproduced any historical version, is being more and more users are concerned about, I believe that in the future there will be a very wide range of users. BakBone's TrueCDP can be any point in time recovery, is the real meaning of the BakBone's TrueCDP, which can perform recovery at any point in time, is a CDP in the true sense of the word, and will have greater advantages than other quasi-CDP products, and will be chosen by more users who care about disaster recovery. Disaster recovery systems are increasingly being emphasized because of their ability to bring about business continuity, but in the process of using them, it is important to bear in mind that there are some misconceptions.
Not choosing the right one for you. Without careful analysis and clear business continuity requirements, the RTO and RPO did not carry out a careful study, either do not do, to do to pursue the most comprehensive, so that may have neglected the most necessary construction, did not effectively meet their needs.
Thinking that the disaster recovery system is omnipotent, exaggerating the role of the disaster recovery system, ignoring the backup system, high availability system construction. In fact, each system has its own role and needs to be built according to actual needs.
No step-by-step phased construction of disaster recovery, always want to wait for the actual maturity of the time to build a comprehensive construction, and even before the construction of data backup system, start to work on the construction of disaster recovery system. Without backup system construction, there is no bottom line to meet the data security, the lack of a complete copy of the data at the critical moment, and spend a lot of financial resources for the construction of the disaster recovery system, but the loss is not worth it.
The selection of multiple disaster recovery technologies is unreasonable, for example, the host system resources can accept host-based replication software to run, but the selection of storage system-based design, resulting in the necessity to use the same type of storage equipment, increasing the overall cost.
Disaster backup for BMR systems always want to use the BMR module that comes with the backup software. In fact, the BMR module that comes with the backup software is more convenient for Window and Linux, but it is not suitable for all Unix systems. In terms of Unix system backup, the system backup tool that comes with Unix and the tape drive that comes with it are very convenient, and a single command can complete the system backup, and you don't have to rely on other servers, which is much better than the BMR module that comes with some backup software, not only is it easy to operate, but it is also much more convenient to use the BMR module. BMR module, not only easy to operate, but also reduce costs. The future of technology development should be a variety of technologies coexist, and the more to meet the needs of the customer way to get the attention of customers.
One of the future developments is that host-based heterogeneous replication technology will have a wider market. Because most customers have heterogeneous host environments, data replication technologies that support heterogeneous environments can take advantage of existing environments and replicate each host with each other. For replication software that does not support heterogeneous environments, it is necessary to purchase the same storage or purchase the same operating system host for data replication, increasing the overall cost of disaster recovery.
Future development of the second is CDP technology. CDP combines the advantages of data backup and data replication, both real-time data protection, but also any point in time of the historical data recovery, will have a more powerful vitality. With the seamless integration of TrueCDP and traditional backup software, more and more users will adopt TrueCDP for disaster recovery system construction. The diagram to the right shows the architecture of the popular BakBone NetVault TureCDP backup system.