如何在 Ubuntu 和 CentOS 7 之間同步執行

我正在嘗試在 Ubuntu 實例和 CentOS 7 實例之間同步數據。這就像一個雙向 rsync，所以我認為unison將是最好的工具。我在兩個實例上都安裝了它，但是當我嘗試連接它們時，我收到一個錯誤，因為版本不同：

unison -testServer . ssh://myuser@myremotehost/efs/home/
Contacting server...
myuser@myremotehost's password:
Fatal error: Received unexpected header from the server:
expected "Unison 2.48\n" but received "Unison 2.40\n\000\000\000\000\017",
which differs at "Unison 2.40".
This can happen because you have different versions of Unison
installed on the client and server machines, or because
your connection is failing and somebody is printing an error
message, or because your remote login shell is printing
something itself before starting Unison.

因此，我嘗試使版本匹配，但是當我查看時，我只看到 Ubuntu 上可用的一個版本。

myuser@mylocalhost:/nas/$ apt policy unison
unison:
 Installed: 2.48.4-1ubuntu1
 Candidate: 2.48.4-1ubuntu1
 Version table:
*** 2.48.4-1ubuntu1 500
       500 http://us.archive.ubuntu.com/ubuntu bionic/universe amd64 Packages
       100 /var/lib/dpkg/status

當我查看 CentOS 7 時，我看不到任何版本

$ yum --showduplicates list unison
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* base: d36uatko69830t.cloudfront.net
* epel: mirror.prgmr.com
* extras: d36uatko69830t.cloudfront.net
* updates: d36uatko69830t.cloudfront.net
Error: No matching Packages to list

但是，我可以毫無問題地安裝它：

$ sudo yum install unison
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* base: d36uatko69830t.cloudfront.net
* epel: d2lzkl7pfhq30w.cloudfront.net
* extras: d36uatko69830t.cloudfront.net
* updates: d36uatko69830t.cloudfront.net
Package unison240-gtk-2.40.128-5.el7.x86_64 already installed and latest version
Nothing to do

我在查找版本時做錯了嗎？我怎樣才能讓它們匹配？

本地主機是：

myuser@mylocalhost:/nas$ cat /etc/*release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=18.04

遠端主機是：

$ cat /etc/*release
CentOS Linux release 7.6.1810 (Core)

根據@Freddy 的評論，關鍵是在 CentOS 上從原始碼編譯一致：

yum install ocaml ocaml-camlp4-devel ctags ctags-etags

cd ~
wget http://www.seas.upenn.edu/~bcpierce/unison//download/releases/stable/unison-2.48.4.tar.gz
tar xvfz unison-2.48.4.tar.gz
cd src
make

sudo cp -v unison /usr/local/sbin/
sudo cp -v unison /usr/bin/

cd ~
rm -fr src

然後你就可以同步執行了：

在本地伺服器上，轉到所需的位置，然後使用

unison -testServer . ssh://myuser@myremotehost//path/to/data/

要做真正的事情，只需-testServer從上面刪除。在這樣做之前tmux也是一個好主意。

引用自：https://unix.stackexchange.com/questions/586417