在linux系统中，我们有时会“不小心”误删除一些文件，如果是自己是测试环境服务器可能“无所谓”。但是一旦发生在客户的生产环境，那就是“重大安全事故”。
我们能不能提前对一些重要的文件系统进行备份，以便当我们真的误删除一些重要的文件时，能够及时恢复呢？本次为大家讲解如何使用xfsdump和xfsrestore命令实现RHEL7 xfs文件系统误删除文件的恢复。
1.实验环境
1.VMWare RHEL7.7
命令：
cat /etc/redhat-release
2.实施步骤
1.虚拟机关机
2.新增一块硬盘大小20G
3.虚拟机开机并查看新增磁盘信息
命令：
lsblk |grep “sdb”
4.对新增磁盘进行分区，大小5GB
命令：
echo -e “onnnpn1nn+5Gnw” | fdisk /dev/sdb
lsblk |grep “sdb”
5.格式化磁盘分区并挂载
命令：
mkfs.xfs -f /dev/sdb1
mkdir -p /tmp/sdb1
mount /dev/sdb1 /tmp/sdb1
6.创建空文件，空目录，普通文件，普通目录
命令：
cd /tmp/sdb1
mkdir a
mkdir b
touch aa
touch bb
touch kong.txt
echo “aaa” >>aa
echo “bbb” >>bb
mv bb b/
7.使用xfsdump命令备份/dev/sdb1分区中的数据至/root/back目录
前提：如果xfsdump未安装，请安装；yum源可用
yum -install -y xfsdump
命令：
mkdir -p /root/back
xfsdump -f /root/back/dump_sdb1 /dev/sdb1
备注：dump_sdb1为自动定义备份文件名称
[root@rhel77 back]# xfsdump -f /root/back/dump_sdb1 /dev/sdb1
xfsdump: using file dump (drive_simple) strategy
xfsdump: version 3.1.7 (dump format 3.0) - type ^C for status and control
============================= dump label dialog ==============================
please enter label for this dump session (timeout in 300 sec)
-> dump_sdb1 #label标签名，可以为空
session label entered: "dump_sdb1"
--------------------------------- end dialog ---------------------------------
xfsdump: level 0 dump of rhel77:/tmp/sdb1
xfsdump: dump date: Sun May 28 19:23:11 2023
xfsdump: session id: b0498d15-755e-4e33-8207-d47830a84bde
xfsdump: session label: "dump_sdb1"
xfsdump: ino map phase 1: constructing initial dump list
xfsdump: ino map phase 2: skipping (no pruning necessary)
xfsdump: ino map phase 3: skipping (only one dump stream)
xfsdump: ino map construction complete
xfsdump: estimated dump size: 30592 bytes
============================= media label dialog =============================
please enter label for media in drive 0 (timeout in 300 sec)
-> sdb1
media label entered: "sdb1" #media标签名，可以为空
--------------------------------- end dialog ---------------------------------
xfsdump: creating dump session media file 0 (media 0, file 0)
xfsdump: dumping ino map
xfsdump: dumping directories
xfsdump: dumping non-directory files
xfsdump: ending media file
xfsdump: media file size 23656 bytes
xfsdump: dump size (non-dir files) : 1088 bytes
xfsdump: dump complete: 12 seconds elapsed
xfsdump: Dump Summary:
xfsdump: stream 0 /root/back/dump_sdb1 OK (success)
xfsdump: Dump Status: SUCCESS
[root@rhel77 back]# ls #查看备份后的信息
dump_sdb1
[root@rhel77 back]#8.模拟删除/tmp/sdb1(/dev/sdb1)下的文件
命令：
cd /tmp/sdb1
rm -rf *
ls
9.执行恢复
命令：
cd /tmp/sdb1
xfsrestore -f /root/back/dump_sdb1 /tmp/sdb1/
ls
tree
备注：dump_sdb1为xfsdump命令备份的文件名称
[root@rhel77 sdb1]# cd /tmp/sdb1
[root@rhel77 sdb1]# xfsrestore -f /root/back/dump_sdb1 /tmp/sdb1/
xfsrestore: using file dump (drive_simple) strategy
xfsrestore: version 3.1.7 (dump format 3.0) - type ^C for status and control
xfsrestore: searching media for dump
xfsrestore: examining media file 0
xfsrestore: dump description:
xfsrestore: hostname: rhel77
xfsrestore: mount point: /tmp/sdb1
xfsrestore: volume: /dev/sdb1
xfsrestore: session time: Sun May 28 19:23:11 2023
xfsrestore: level: 0
xfsrestore: session label: "dump_sdb1"
xfsrestore: media label: "sdb1"
xfsrestore: file system id: f41c9297-c680-4555-887b-673d47c5693e
xfsrestore: session id: b0498d15-755e-4e33-8207-d47830a84bde
xfsrestore: media id: 0d886f27-6182-408d-89a1-ee0cf1265645
xfsrestore: using online session inventory
xfsrestore: searching media for directory dump
xfsrestore: reading directories
xfsrestore: 3 directories and 5 entries processed
xfsrestore: directory post-processing
xfsrestore: restoring non-directory files
xfsrestore: restore complete: 0 seconds elapsed
xfsrestore: Restore Summary:
xfsrestore: stream 0 /root/back/dump_sdb1 OK (success)
xfsrestore: Restore Status: SUCCESS
[root@rhel77 sdb1]# ls
a aa b kong.txt
[root@rhel77 sdb1]# tree
.
├── a
├── aa
├── b
│ └── bb
└── kong.txt
2 directories, 3 files
[root@rhel77 sdb1]#至此，被删除的文件和目录恢复成功！
备注：
1.xfsdump备份和xfsrestore恢复磁盘的前提是磁盘分区始终要处于挂载状态
2.xfsdump -f /root/back/dump_sdb1 /dev/sdb1。
xfsdump -f $destination $source
xfsdump命令备份时，$source只可以使用/dev/sdb1磁盘分区，不可以使用 /tmp/sdb1(/dev/sdb1磁盘分区的挂载点)
3.xfsrestore能够恢复为空的文件和目录
4.xfsrestore -f /root/back/dump_sdb1 /tmp/sdb1
xfsrestore -f $source $destination
xfsrestore命令恢复时，$destination既可以是/tmp/sdb1(/dev/sdb1磁盘分区的挂载点)，也可以是其它目录，但不能直接使用/dev/sdb1磁盘分区名称
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