First, RsyncRsync (remote synchronize), as the name implies, can know that this is a remote data synchronization tool, you can quickly sync files between multiple hosts via Lan/wan. Rsync uses the so-called "rsync algorithm" to synchronize files between local and remote two hosts, which transmits only the different portions of two files, rather than the entire transfer every time, so it is quite fast. Rsync was originally a tool for replacing RCP and is currently maintained by rsync.samba.org, so the format of the rsync.conf file is similar to the main configuration file for Samba. Rsync can be used via rsh or SSH, or run in daemon mode, and Rsync server will open a port 873 when running in daemon mode, waiting for the client to connect. When connected, Rsync server checks that the password matches and, if checked with a password, can start the file transfer. When the first connection is complete, the entire file is transferred once, and then only incremental backups are made. Rsync supports most Unix-like systems, which are well tested on Linux, Solaris, and BSD. In addition, it also has a corresponding version under the Windows platform, such as Cwrsync and Sync2nas tools. The basic features of rsync are as follows: 1. Can be mirrored to save the entire directory tree and file system; 2. It is easy to maintain the original file permissions, time, soft and hard links, etc. 3. No special permission is required to install; 4. Optimized process, high file transfer efficiency; 5. You can transfer files using rsh, SSH, etc. , of course, can also be connected via a direct socket; 6. Anonymous transmission is supported.
Second, UnisonUnison is a two-way file synchronization tool that can be used under both Windows and UNIX platforms to keep content consistent between two folders (local or network). Unison has some other synchronization tools or file system of the same characteristics, but also has its own features: 1, cross-platform use, 2, the kernel and user rights do not have special requirements; 3, Unison is bidirectional, it can automatically handle the two-minute copy of the update conflict-free parts, Conflicting parts will be displayed to allow users to choose the update strategy, as long as the two host can be connected, you can run unison, you can directly use the socket connection or secure SSH connection, the bandwidth requirements are not high, using similar to Rsync Compression transport protocol. One drawback of unison bidirectional synchronization is that, for files with the same name being modified in two synchronized folders, Unison is not synchronized because Unison cannot judge that.
Third, DRBDDRBD Features: 1, DRBD is a block device 2, can be used for high-availability cluster (HA) 3, through the network to implement block device data real-time mirroring 4, similar to a network RAID-1 so-called DRBD, is a distributed replication block device, is a TCP/IP network to implement block device data Scenarios for real-time mirroring. , which can be used in high availability (HA). It is similar to a network RAID-1 feature. When you write data to the local file system, the data is also sent to another host on the network. Recorded in a file system in the same form. Local (master node) and remote host (standby node) Data to ensure real-time synchronization. When the local system fails, a copy of the same data is retained on the remote host and can continue to be used. Using the DRBD feature in high Availability (HA) can be used instead of a shared disk array. Because the data exists both on the local host and on the remote host, The remote host can continue to service as long as it uses the backup data on top of it.
|
Rsync |
Unison |
Drbd |
| Brief introduction |
The Remote Data Sync tool allows you to quickly sync files between multiple hosts via Lan/wan. Currently maintained by rsync.samba.org |
Unison is a two-way file synchronization tool that can be used under both Windows and UNIX platforms to keep content consistent between two folders (local or network). Development is currently discontinued. |
DRBD, a distributed replication block device, is a scheme for real-time mirroring of block device data through TCP/IP networks. , which can be used in high availability (HA). It resembles a network RAID-1 function. |
| Functions and characteristics |
1. The image holds the entire directory tree and the file system; 2. Maintain the original file permissions, time, soft and hard links, etc. 3. No special permission is required to install; 4. Optimize the process, file transfer efficiency is high; Use the rsync algorithm to synchronize the different portions of two files instead of the whole transfer each time; 5. Rsh can be used , SSH and other means to transfer files, but also through a direct socket connection; 6. Anonymous transmission is supported. |
1, cross-platform use; 2, no special requirements for kernel and user rights;
3, Support bidirectional synchronization, can automatically process two copies of the update without conflicting parts, the conflicting parts will be displayed to allow users to choose the update strategy, 4, you can directly use the socket connection or secure SSH connection, the bandwidth requirements are not high, using similar rsync compression Transfer protocol. |
1, DRBD is a block device 2, can be used for high-availability cluster (HA) 3, through the network to achieve block device data real-time mirroring 4, similar to a network RAID-1 |
| Using the Platform |
Unix-like platform (Linux, Solaris, BSD) Windows platform version: Cwrsync |
Windows Platform Unix/linux Platform |
Linux Platforms |
| Dependence |
No |
No |
Kernel support Required |
| Transmission mode |
RSH, SSH, socket connection, daemon mode |
Socket connection or secure SSH connection mode |
Real-time mirroring of block device data via TCP/IP network |
| Stability |
High |
Normal (timeout critical) |
High |
| Sync speed |
Fast |
Small file synchronization speed: Fast large file synchronization speed: General |
Small file sync Speed: Fast large file sync speed: Slow |
| Disadvantages |
Bidirectional transfers are not supported |
Timeout critical |
Two-way transmission is not supported, slow transmission speed |
Comparison of Rsync, Unison and DRBD
Summary:Rsync, Unison, and DRBD three software, although all are the tools to synchronize backup data, but each has its own function. Rsync only supports one-way synchronization, but its synchronization speed is the fastest among the three, the right to say that its synchronization speed is unmatched by the other two. At the same time, rsync+inotify can be used to achieve real-time touch sync update files. Unison supports bidirectional synchronization, there is no requirement for kernel and user rights, but its synchronization speed is particularly slow, often with timeouts. DRBD is used for high availability (HA), similar to a network RAID-1 function, and is slower. By installing the rsync, Unison and DRBD three software, and testing its capabilities, it is found that each of the three has its advantages. Can not simply evaluate who is inferior, should be for the user's use of the use of tools to choose. http://qq85609655.iteye.com/blog/1879416
Comparison of Rsync, Unison and DRBD
