1.备份原有Jira的db和安装文件，以便回退版本
数据路备份命令：
Mysqldump –h(数据库地址) –u(用户名) –p(密码) –P(数据库端口号) (需要备份的数据库名称) > xxx.sql
2.下载jira6版本的最高版本，下载地址为https://www.atlassian.com/software/jira/download-archives，文件名为：atlassian-jira-6.4.14-x64.bin
3.检查6.3.6和6.4.14的兼容性，我们发现只有一个插件可能会存在冲突就是汉化jira所用到的jar包这个不用在意,还有另一个jira agile插件所用的jar包可能需要升级并不产生冲突。
4.sh atlassian-jira-6.4.14-x64.bin 按照提示来进行升级安装的操作
This will install JIRA Software 6.4.14 on your computer.
OK [o, Enter], Cancel [c]
o
Choose the appropriate installation or upgrade option.
Please choose one of the following:
Express Install (use default settings) [1], Custom Install (recommended for advanced users) [2], Upgrade an existing JIRA installation [3, Enter]
3
Existing installation directory:
[/opt/atlassian/jira]
回车
Back up JIRA home directory
The upgrade process will automatically back up your JIRA installation
directory. You can also choose to back up your existing JIRA home directory.
Both directories are backed up as zip archive files in their respective
parent directory locations.
We strongly recommend choosing this option in the unlikely event that you
experience problems with the upgrade and may require these backups to
restore your existing JIRA installation.
If you have many attachments in your JIRA home directory, the zip archive of
this directory may consume a significant amount of disk space.
Back up JIRA home directory?
Yes [y, Enter], No [n]
这里提示你需不需要备份，jira之前安装的一些插件需要手动备份。之前我们第一步已经做过备份了这里输入n
checking for local modifications.
List of modifications made within JIRA directories.
The following provides a list of file modifications within the
atlassian-jira directory.
Modified files:
(none)
Removed files:
(none)
Added files:
atlassian-jira/WEB-INF/lib/mysql-connector-java-5.1.44-bin.jar
这里是检查本地的一些修改，我们可以看到我们新增的连接后台数据库所用的jar包，这里直接确认回车就可以了。
Checking if your instance of JIRA Software is running
Upgrade check list
Back up your external database
We strongly recommend you back up your JIRA Software database if you have
not already done so.
Please refer to the following URL for back up guidelines:
http://docs.atlassian.com/jira/jadm-docs-0711/Backing+up+data
Check plugin compatibility
Check that your non-bundled plugins are compatible with JIRA Software
6.4.14
For more information see our documentation at the following URL:
http://docs.atlassian.com/jira/jadm-docs-0711/Upgrading+JIRA+applications
Please ensure you have read the above checklist before upgrading.
Your existing JIRA installation is about to be upgraded! Do you want to proceed?
Upgrade [u, Enter], Exit [e]
这里是确认之上的操作jira版本即将升级，我们直接输入u就可以了。
Your instance of JIRA is currently being upgraded.
Checking if JIRA has been shutdown…
Backing up the JIRA installation directory
Deleting the previous JIRA installation directory…
Extracting files …
Please wait a few moments while JIRA Software is configured.
Installation of JIRA Software 6.4.14 is complete
Start JIRA Software 6.4.14 now?
Yes [y, Enter], No [n]
加载jira升级版本的一些配置需要等一段时间，等待时间要看服务器的性能，立即启动jira我们选择y。
JIRA Software 7.11.2 can be accessed at http://localhost:8080
JIRA Software may take several minutes to load on first start up.
Finishing installation …
这里我们可以看到6.4.14版本的jira已经安装完成。
5.之后我们输入地址，输入用户名密码，进入系统插件管理，把能升级的插件全部升级到最新版本
6.只有再从官网上下载https://www.atlassian.com/software/jira/download-archives，文件名为：atlassian-jira-software-7.0.0-jira-7.0.0-x64.bin，然后再进行一遍上述4步骤的操作，版本升级为7.0.0