File sync rsync + ssh + inotify + unison implementation in Linux

1. Use rsync + ssh software for regular file backup and Incremental backup, but not for real-time backup, so the effect is not very good.
Server A (ip: 2.2.2.135 ):
[Root @ CentOS ~] # Ifconfig eth0 -- View IP addresses
Eth0 Link encap: Ethernet HWaddr 08: 00: 27: 56: AA
Inet addr: 2.2.2.135 Bcast: 2.20.255.255 Mask: 255.0.0.0
Inet6 addr: fe80: a00: 27ff: fe56: aaaa/64 Scope: Link
Up broadcast running multicast mtu: 1500 Metric: 1
RX packets: 13072 errors: 0 dropped: 0 overruns: 0 frame: 0
TX packets: 328 errors: 0 dropped: 0 overruns: 0 carrier: 0
Collisions: 0 FIG: 1000
RX bytes: 1009592 (985.9 KiB) TX bytes: 31733 (30.9 KiB)
[Root @ centos ~] # Vim/etc/hosts -- Add the following lines
2.2.2.145 centos1
2.2.2.135 centos
[Root @ centos ~] # Yum install rsync -- install the rsync software. Remember to install all the two computers.
[Root @ centos ~] # Ssh-keygen-t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/. ssh/id_rsa ):
/Root/. ssh/id_rsa already exists.
Overwrite (y/n )? Y
Enter passphrase (empty for no passphrase ):
Enter same passphrase again:
Your identification has been saved in/root/. ssh/id_rsa.
Your public key has been saved in/root/. ssh/id_rsa.pub.
The key fingerprint is:
12: c6: 7b: 6a: 12: 4a: 15: c8: 8b: 0f: 90: 54: 02: fa: 08: 27 root @ centos
The key's randomart image is:
+ -- [RSA 2048] ---- +
| + =. O. |
| ++ O |
| E... + |
| + =... O |
|. Oo. o S |
|... + |
|. O |
| O |
|
+ ----------------- +
[Root @ centos ~] # Scp ~ /. Ssh/id_rsa.pub 2.2.2.145:/root/. ssh/authorized_keys -- put the public key on another server
[Root @ centos ~] # Ssh 2.2.2.145 -- no password for login
Last login: Tue Dec 17 09:46:05 2013 from centos
[Root @ centos1 ~] #

Server B (ip: 2.2.2.145 ):
[Root @ centos1 ~] $ Ifconfig eth0 -- View IP Address
Eth0 Link encap: Ethernet HWaddr 08: 00: 27: 56: AA
Inet addr: 2.2.2.145 Bcast: 2.2.2.255 Mask: 255.255.255.0
Inet6 addr: fe80: a00: 27ff: fe56: aaaa/64 Scope: Link
Up broadcast running multicast mtu: 1500 Metric: 1
RX packets: 14005 errors: 0 dropped: 0 overruns: 0 frame: 0
TX packets: 503 errors: 0 dropped: 0 overruns: 0 carrier: 0
Collisions: 0 FIG: 1000
RX bytes: 1081748 (1.0 MiB) TX bytes: 46832 (45.7 KiB)
[Root @ centos1 ~] $ Vim/etc/hosts -- Add the following two lines
2.2.2.135 centos
2.2.2.145 centos1
[Root @ centos1 ~] $ Ping 2.2.2.135-c 1 -- connect
PING 2.2.2.135 (2.2.2.135) 56 (84) bytes of data.
64 bytes from 2.2.2.135: icmp_seq = 1 ttl = 64 time = 0.438 MS
--- 2.2.2.135 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0 ms
Rtt min/avg/max/mdev = 0.438/0.438/0.438/0.000 MS
[Root @ centos ~] # Yum install rsync
PING 2.2.2.135 (2.2.2.135) 56 (84) bytes of data.
64 bytes from 2.2.2.135: icmp_seq = 1 ttl = 64 time = 0.438 MS
--- 2.2.2.135 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0 ms
Rtt min/avg/max/mdev = 0.438/0.438/0.438/0.000 MS
[Root @ centos ~] # Yum install rsync -- install software
[Root @ centos1 ~] # Ssh-keygen-t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/. ssh/id_rsa ):
/Root/. ssh/id_rsa already exists.
Overwrite (y/n )? Y
Enter passphrase (empty for no passphrase ):
Enter same passphrase again:
Your identification has been saved in/root/. ssh/id_rsa.
Your public key has been saved in/root/. ssh/id_rsa.pub.
The key fingerprint is:
4b: 74: 44: ca: 38: 50: 17: 25: 3a: 1e: b0: ac: a4: 7d: f3: be root @ centos1
The key's randomart image is:
+ -- [RSA 2048] ---- +
| O... ++ |
|. + = + |
|. O * +. |
| +... =. |
|. O. S |
|. O... |
|... |
|. |
| E. |
+ ----------------- +
[Root @ centos1 ~] # Scp ~ /. Ssh/id_rsa.pub 2.2.2.135:/root/. ssh/authorized_keys
[Root @ centos1 ~] $ Rsync 2.2.2.135:/home/*. txt/home/-- remotely copy the file.-r is the directory.
[Root @ centos1 ~] $ Ll/home/*. txt -- copied successfully
-Rw-r -- 1 root 36 Dec 16 14:40/home/1.txt
-Rw-r -- 1 root 12 Dec 16 14:34/home/2.txt
-Rw-r -- 1 root 0 Dec 16 15:48/home/3.txt
[Root @ centos1 ~] $ Crontab-e
* 24 ***/usr/bin/rsync 2.2.2.135:/home/*. txt/home/-- backup at 24 o'clock every day

2. rsync + ssh + inotify for real-time file backup (inotify File System Monitoring)
Server A (ip: 2.2.2.135): Backup File

[Root @ centos1 samba] $ tar xvf inotify-tools-3.14.tar.gz
[Root @ centos1 samba] $ cd inotify-tools-3.14
[Root @ centos1 inotify-tools-3.14] $./configure -- prefix =/usr/local/inotify & make install -- install software
[Root @ centos inotify-tools-3.14] # cd/usr/local/inotify/
[Root @ centos inotify] # ll
Total 16
Drwxr-xr-x. 2 root 4096 Dec 16 16:08 bin
Drwxr-xr-x. 3 root 4096 Dec 16 16:08 include
Drwxr-xr-x. 2 root 4096 Dec 16 16:08 lib
Drwxr-xr-x. 4 root 4096 Dec 16 16:08 share
[Root @ centos inotify] # cd bin/
[Root @ centos bin] # ll
Total 72
-Rwxr-xr-x. 1 root 36447 Dec 16 16:08 inotifywait
-Rwxr-xr-x. 1 root 34961 Dec 16 16:08 inotifywatch
[Root @ centos bin] # vim start. sh
#! /Bin/sh
SRC =/home/
DST =/home/
IP = 2.2.2.145
/Usr/local/inotify/bin/inotifywait-mrq-e modify, delete, create, attrib $ {SRC} | while read status
Do
/Usr/bin/rsync-auvg -- delete $ DST $ IP: $ SRC & -- run in the background
If (echo "$? "=" 0 "); then
Echo 'date + % d': back OK>/home/1.log -- there is a single quotation mark before the date
Else
Echo 'date + % d': error>/home/1.log
Done
[Root @ centos1 bin] # chmod o + x start. sh
[Root @ centos1 bin] #./start. sh &
[2] 2915
[Root @ centos1 bin] # ll/home/1
Total 8
-Rw-r -- 1 root 36 Dec 16 14:40 1.txt
-Rw-r -- 1 root 12 Dec 16 14:34 2.txt
-Rw-r -- 1 root 0 Dec 17 10:58 3.txt
[Root @ centos1 bin] # mkdir/home/1/{1, 2, 3}
[Root @ centos1 bin] # ll/home/1
Total 20
Drwxr-xr-x 2 root 4096 Dec 17 :31 1
-Rw-r -- 1 root 36 Dec 16 14:40 1.txt
Drwxr-xr-x 2 root 4096 Dec 17 11: 31 2
-Rw-r -- 1 root 12 Dec 16 14:34 2.txt
Drwxr-xr-x 2 root 4096 Dec 17 11: 31 3
-Rw-r -- 1 root 0 Dec 17 10:58 3.txt
[Root @ centos1 bin] # cat/home/1.log -- logs are recorded and succeeded.
: Back OK
: Back OK
: Back OK
: Back OK
[Root @ centos1 bin] # -- go to 2.2.2.145 to check whether the file is synchronized.

Server B (ip: 2.2.2.145): used to read files
[Root @ centos1 1] # ifconfig eth0
Eth0 Link encap: Ethernet HWaddr 08: 00: 27: 56: AA
Inet addr: 2.2.2.145 Bcast: 2.2.2.255 Mask: 255.255.255.0
Inet6 addr: fe80: a00: 27ff: fe56: aaaa/64 Scope: Link
Up broadcast running multicast mtu: 1500 Metric: 1
RX packets: 38855 errors: 0 dropped: 0 overruns: 0 frame: 0
TX packets: 12226 errors: 0 dropped: 0 overruns: 0 carrier: 0
Collisions: 0 FIG: 1000
RX bytes: 3390394 (3.2 MiB) TX bytes: 1557639 (1.4 MiB)
[Root @ centos1 1] # ll/home/1 -- server B can see
Total 20
Drwxr-xr-x 2 root 4096 Dec 17 :31 1
-Rw-r -- 1 root 36 Dec 16 14:40 1.txt
Drwxr-xr-x 2 root 4096 Dec 17 11: 31 2
-Rw-r -- 1 root 12 Dec 16 14:34 2.txt
Drwxr-xr-x 2 root 4096 Dec 17 11: 31 3
-Rw-r -- 1 root 0 Dec 17 10:58 3.txt

3. Two-way synchronization of unison + ssh files, unable to achieve real-time two-way Synchronization
1) install the unison Software
[Root @ centos1 samba] # tar xvf ocaml-3.12.1.tar.gz
[Root @ centos1 samba] # cd ocaml-3.12.1
[Root @ centos1 ocaml-4.01.0] #./configure & make install
[Root @ centos1 ocaml-4.01.0] # cd ..
[Root @ centos1 samba] # tar xvf unison-2.40.63.tar.gz
[Root @ centos1 samba] # cd unison-2.40.63
[Root @ centos1 unison-2.40.63] # make UISTYLE = text
[Root @ centos1 unison-2.40.63] # mkdir/root/bin
[Root @ centos1 unison-2.40.63] # make install
[Root @ centos1 unison-2.40.63] # cp/root/bin/unison/usr/bin

2) password-less ssh Login (Server 1, Server 2, and password-less)
[Root @ centos home] # ssh-keygen-t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/. ssh/id_rsa ):
/Root/. ssh/id_rsa already exists.
Overwrite (y/n )? Y
Enter passphrase (empty for no passphrase ):
Enter same passphrase again:
Your identification has been saved in/root/. ssh/id_rsa.
Your public key has been saved in/root/. ssh/id_rsa.pub.
The key fingerprint is:
E3: 70: 96: 80: 20: 8b: e8: a9: 6f: 7a: 00: 64: 5f: 8b: 86: 90 root @ centos
The key's randomart image is:
+ -- [RSA 2048] ---- +
|... |
| E =. o |
| B o + o |
| O... +... |
|. O. S |
| O =. |
|... |
|. O |
|. +. |
+ ----------------- +
[Root @ centos home] # scp ~ /. Ssh/id_rsa.pub 2.2.2.145:/root/. ssh/authorized_keys
Root@2.2.2.145's password:
Id_rsa.pub 100% 393 0.4KB/s
[Root @ centos home] # ssh 2.2.2.145 -- success, no password required
Last login: Tue Dec 17 13:25:15 2013 from centos
[Root @ centos1 ~] #

3) Server 2 Login Server 1 No Password
[Root @ centos1 unison-2.40.63] # ssh-keygen-t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/. ssh/id_rsa ):
/Root/. ssh/id_rsa already exists.
Overwrite (y/n )? Y
Enter passphrase (empty for no passphrase ):
Enter same passphrase again:
Your identification has been saved in/root/. ssh/id_rsa.
Your public key has been saved in/root/. ssh/id_rsa.pub.
The key fingerprint is:
Be: 43: 3a: 24: 4c: 83: fe: bd: 22: e2: ed: c2: 89: 7e: AB: c9 root @ centos1
The key's randomart image is:
+ -- [RSA 2048] ---- +
|
|
|. |
|. O |
|. O. S |
|. O... |
| O... + o. |
| ++. O +... |
| OE =... o... |
+ ----------------- +
[Root @ centos1 unison-2.40.63] # scp ~ /. Ssh/id_rsa.pub 2.2.2.135:/root/. ssh/authorized_keys
[Root @ centos1 unison-2.40.63] # ssh 2.2.2.135
Last login: Tue Dec 17 13:26:06 2013 from centos1
[Root @ centos ~] #

4) Server 1 and 2 file synchronization
[Root @ centos1 bin] # unison/home ssh: // root@2.2.2.145:/home -- file sync
[Root @ centos1 bin] # unison/home ssh: // root@2.2.2.145:/home -- path directory -- synchronize only the specified directory

Rsync details: click here
Rsync: click here

Recommended reading:

Monitor host files and directories using inotifywait

Using inotify + rsync for Linux File batch update

Inotify-tools + rsync real-time file synchronization installation and configuration

Complete rsync synchronization Configuration