数据库运行硬件或系统环境如果发生了不可恢复的故障，这时只能采用异机恢复的方式恢复数据库。以下通过例子介绍异机恢复的过程。

一、硬件环境

192.168.237.101

数据库运行源主机

192.168.237.102

数据库恢复目标机（异机）

192.168.237.103

数据库备份所在主机 REPO_DB

二、初始化备份环境

在 103 主机配置 sys_backup.conf ，内容如下：

# target db style enum: single/cluster
_target_db_style="single"

one kingbase node IP

just provide one IP, script will use 'repmgr cluster show' get other node IP

_one_db_ip="192.168.237.101"

local repo IP, inner-REPO, must be same as one_db_ip, means repo located in one db node

outer repo IP, outer-REPO, means repo located in outer node

_repo_ip="192.168.237.103"

label of this cluster

_stanza_name="kingbase"

OS user name of database

_os_user_name="c5"

!!!! dir to store the backup files

should be accessable for the OS user

_repo_path="/home/c5/bak"

count of keep, over the count FULL-backup will be remove

_repo_retention_full_count=5

count of days, interval to do FULL-backup

_crond_full_days=7

count of days, interval to do DIFF-backup

_crond_diff_days=0

count of days, interval to do INCR-backup

_crond_incr_days=1

HOUR to do the FULL-backup

_crond_full_hour=2

HOUR to do the DIFF-backup

_crond_diff_hour=3

HOUR to do the INCR-backup

_crond_incr_hour=4

OS cmd define

_os_ip_cmd="/sbin/ip"
_os_rm_cmd="/bin/rm"
_os_sed_cmd="/bin/sed"
_os_grep_cmd="/bin/grep"

!!! these follow 4 parameter ONLY for single style

data dir of single

_single_data_dir="/home/c5/ES/V8/data"

bin dir of single

_single_bin_dir="/home/c5/ES/V8/Server/bin"

database user of single

_single_db_user="system"

database port of single

_single_db_port="54321"

运行 sys_backup.sh init ， 验证数据库备份正常。

三、进行异机恢复

这里模拟101 环境宕机的情况。

1、ssh 互信配置

需要配置新的数据库主机 (102) 与备份主机 (103) 间的互信关系。因为数据库恢复时，需要从远程拷贝文件，需要配置相互间免密登录。

2、修改 REPO_IP 103 主机的 sys_rman.conf

[c5@nn03 bak]$ cat sys_rman.conf

Genarate by script at 20220114162108, should not change manually

[kingbase]
kb1-path=/home/c5/ES/V8/data --新数据库主机数据目录
kb1-port=54321
kb1-user=system
kb1-host=192.168.237.102 --新数据库主机
kb1-host-user=c5

[global]
repo1-path=/home/c5/bak
repo1-retention-full=5
log-path=/home/c5/ES/V8/Server/log
log-level-file=info
log-level-console=info
log-subprocess=y
process-max=4

default gz, support: gz none

compress-type=gz
compress-level=3

3、102 主机配置备份目录

创建目录：/home/c5/bak

创建 sys_rman.conf 文件

这个文件可以从原主机（101）拷贝，也可以从 备份主机拷贝，再进行修改

[c5@nn02 bak]$ cat sys_rman.conf

Genarate by script at 20220114162109, should not change manually

[kingbase]
kb1-path=/home/c5/ES/V8/data --目标数据库路径
[global]
repo1-host=192.168.237.103 --REPO数据库所在主机
repo1-host-user=c5
repo1-host-config=/home/c5/bak/sys_rman.conf
repo1-path=/home/c5/bak
log-path=/home/c5/ES/V8/Server/log
log-level-file=info
log-level-console=info

4、在新数据库主机进行恢复

在102 主机进行恢复：

[c5@nn02 ~]$ sys_rman --config=/home/c5/bak/sys_rman.conf --stanza=kingbase --log-path=/tmp restore

5、验证恢复准确性