How Do I Perform Server Differential Backup? How do two servers back up each other?

It is recommended that you can do a high-availability server cluster, which is what we often say, a dual-machine hot standby system, so that you can achieve the results you want, when server A goes down, server B can be replaced immediately, and there will not be too many time gaps. It will not affect your work.

The so-called dual-node hot standby is to install the central server as two servers that back up each other, and only one server is running at the same time. When one of the running servers fails and cannot be started, the other backup service, Orange Macro, will quickly and automatically start and run. Let's take a look at the implementation process under win2000 server edition.

1. Overview of hardware preparation and basic installation.

Web servers two.

Network service network card four.

Server hard disks: Two pieces.

SCSI Disk Array a.

SCSI hard disks 3 pieces.

The first is to configure both servers as dual network cards and install win2000 advance server (advanced server version) separately. Then configure the network environment to make it smooth: join the two servers to the domain, become domain members, and set administrator privileges on each server.

In addition, it should be noted that all disks must be set up as basic disks and split into NTFS format partitions, and the disk array partitions must be larger than 2. Finally, the three SCSI hard disks are made into a disk array, and the author recommends RAID 5 (when configuring the array, it must be noted that a partition of at least 1G is separated to store the detection points and log files of the configuration database).

Second, the specific installation points.

Configure the server network environment points.

1. In the previous step, we installed dual network cards on both servers, one for connecting to the public network (Internet) and the other for connecting to the internal LAN.

Establish point-to-point communication and cluster status signals for the network card connected to the internal LAN, and then connect the cluster to the public network with the public network adapter of each terminal, where the customer resides.

2. After win2000 advanced server version is installed, start to configure the network parameters of each server. In the network connection, change the public network to "Extranet", and the LAN to "Intranet", and then specify the IP addresses of the respective network cards of the two servers as:

Server B: The public IP address is: , the private IP address is: , and the subnet mask is: The gateway is:

Installation Service Software Essentials.

Configure Server A

1. Turn off all devices before turning on the disk array.

2. Start Server A and log in to the domain with the pre-set administrator account; Then add the "Cluster Service" component to the Add Removal Program option, and note that this component is set as the first node of the cluster during the installation process, and then create the cluster name (whichever is acceptable, for example.

myserver）。

3. Since we only have a shared disk array, we should configure all the partitions in this array as cluster disks.

4. Start configuring the cluster network. Extranet.

Incremental backup records changes for each time on the basis of the first full backup. Because incremental backups determine whether the data has changed before backup, and only record each change.

Differential backup records the difference between the latest data and the first full backup on the basis of the first full backup. To put it simply, differential backup is a process of accumulating changes: after a full backup, the changes of the first day are recorded on the first day, the changes of the first day and the second day are recorded on the second day, and so on.

In contrast, incremental backups have the greatest benefit in that they require the least amount of storage space (for the same change), have the fastest backups, and have the longest data recovery time. On the other hand, the data recovery time of differential backups is relatively short, and the storage space required for backups is larger than that of incremental backups.

Therefore, the choice of backup method should be based on the actual needs of backup storage space, backup speed, recovery time, etc.

Differences between full, incremental, and differential backups:

A full backup backs up all data, while incremental backups and differential backups only back up changed data.

Compared with incremental and differential backups, full backups have less time, higher efficiency, and occupy less disk space.

Difference between differential and incremental backups:

1) Differential backup only backs up the changed data on the basis of a full backup; Incremental backup: The previous backup is the basic backup, and the data is changed.

2) Differential backup only has a dependency relationship with a full backup, not with the previous backup; Incremental backups have dependencies on the previous backup and remain relevant to full backups.

Full backup.

Backing up all selected folders does not depend on the archive properties of the files to determine which files to back up.

During the backup process, any existing tags are cleared, and each file is marked as backed up, in other words, the archive properties are cleared).

During a differential backup, only those selected files and folders that are marked are backed up. It does not clear the markup, i.e., the file is not marked as backed up after backup, in other words, it does not clear the archive attributes).

During an incremental backup, only the selected files and folders that are marked are backed up, and it clears the markers, i.e., the files are marked after the backup, in other words, the archive properties are cleared. ）

An example of a combination of different backup types.

Full and differential backups.

Full backups are taken on Monday and differential backups are taken from Tuesday to Friday. If the data is corrupted on Friday, you only need to restore the full backup on Monday and the differential backup on Thursday. This strategy takes more time to back up your data, but less time to restore your data.

Full and incremental backups.

Full backups are taken on Mondays and incremental backups are taken from Tuesday to Friday. If the data is corrupted on Friday, you need to restore the normal backup on Monday and all incremental backups from Tuesday to Friday. This strategy takes more time to back up your data, but less time to restore your data.

Oh, landlord, if you can do other backups, then to do differential backup, you only need to select "differential backup" when doing the same operation"Or in some professional backup software"Backup Changes" This is a differential backup.

You can set one up quickly, or you won't deduct points.

1. Dual-machine hot standby. Array card + scheme is determined according to needs. In the event of a hardware accident, you can quickly switch to another one.

2. Local daily backup: local backup + heterogeneous backup. Database backup can take the automatic backup mechanism of different databases, local and LAN backup. If necessary, it can be backed up as a system image, and it can be quickly restored in case of a virus.

3. Remote disaster recovery backup: transfer data to other places (such as mobile hard disks) on a regular basis as needed. In the event of a catastrophic accident, such as a fire in the computer room, it can be quickly rebuilt. (Different from real remote disaster recovery technology, this is only a concept of disaster recovery.)

Authorized.

Backups and differential backups are generally used when software exits backup data, or when used by a backup service.

For example, "A" is the source data file (data in use) backup, which means that A is directly backed up to one: sub A, which is exactly the same as A.

Differential backup means: when A changes, the data may increase or decrease, anyway, it is not A, this time is changed after comparison before backup, and the backup becomes A+ or B.