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导读 | 本文中将详细介绍如何从已删除的物理卷或故障磁盘场景中恢复。 |
Centos8
下面使用了 /dev/sd[a-c]
三块磁盘,将他们划入一个卷组,创建两个逻辑卷:
# Create pv
[root@localhost ~]# pvcreate /dev/sda
[root@localhost ~]# pvcreate /dev/sdb
[root@localhost ~]# pvcreate /dev/sdc
# Create VG
[root@localhost ~]# vgcreate vg_data /dev/sd[a-c]
# Create LV
[root@localhost ~]# lvcreate -L 25G -n lv_data vg_data
[root@localhost ~]# lvcreate -L 25G -n lv_log vg_data
下面列出逻辑卷的分配使用信息:
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/nvme0n1p2 cl lvm2 a-- <19.00g <2.00g
/dev/sda vg_data lvm2 a-- <20.00g 0
/dev/sdb vg_data lvm2 a-- <20.00g <9.99g
/dev/sdc vg_data lvm2 a-- <20.00g 0
[root@localhost ~]# vgs
VG #PV #LV #SN Attr VSize VFree
cl 1 2 0 wz--n- <19.00g <2.00g
vg_data 3 2 0 wz--n- <59.99g <9.99g
[root@localhost ~]# lvs -a -o +devices
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert Devices
root cl -wi-ao---- 15.00g /dev/nvme0n1p2(512)
swap cl -wi-ao---- 2.00g /dev/nvme0n1p2(0)
lv_data vg_data -wi-a----- 25.00g /dev/sda(0)
lv_data vg_data -wi-a----- 25.00g /dev/sdb(0)
lv_log vg_data -wi-a----- 25.00g /dev/sdc(0)
lv_log vg_data -wi-a----- 25.00g /dev/sdb(1281)
在根目录创建两个文件夹 /data 和 /log,格式化逻辑卷,挂载逻辑卷,并存放一些数据:
[root@localhost ~]# mkdir /data /logs
[root@localhost ~]# mkfs.xfs /dev/vg_data/lv_data
[root@localhost ~]# mkfs.xfs /dev/vg_data/lv_log
[root@localhost ~]# mount /dev/vg_data/lv_data /data
[root@localhost ~]# mount /dev/vg_data/lv_log /data
[root@localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 880M 0 880M 0% /dev
tmpfs 897M 0 897M 0% /dev/shm
tmpfs 897M 8.7M 888M 1% /run
tmpfs 897M 0 897M 0% /sys/fs/cgroup
/dev/mapper/cl-root 15G 1.9G 14G 13% /
/dev/nvme0n1p1 976M 183M 726M 21% /boot
tmpfs 180M 0 180M 0% /run/user/0
/dev/mapper/vg_data-lv_log 25G 211M 25G 1% /data
[root@localhost ~]# touch /data/file{1..10}.txt
[root@localhost ~]# touch /logs/text{1..10}.log
这两种情况是意外删除的物理卷或发生故障的磁盘,通过运行 pvremove 命令删除了任何一个物理卷,或者从虚拟机中移除某一块物理磁盘。
下面从虚拟机中移除一块物理磁盘:
重启系统之后,发现不能挂载 lv_data 和 lv_log 逻辑卷了,/dev 目录中找不到 vg_data
卷组。
如果该逻辑卷设置为开机自动启动了,磁盘发生故障后,由于两个逻辑卷无法挂载文件系统,因此重新引导不能进入系统。只能通过进入单用户模式,并注释 fstab
配置文件里面和该逻辑卷相关的条目。
下面从虚拟机中添加一个新的物理磁盘,新添加的磁盘会变成 /dev/sdc
[root@localhost ~]# lsblk -S
NAME HCTL TYPE VENDOR MODEL REV TRAN
sda 6:0:0:0 disk VMware, VMware Virtual S 1.0 spi
sdb 6:0:2:0 disk VMware, VMware Virtual S 1.0 spi
sdc 6:0:3:0 disk VMware, VMware Virtual S 1.0 spi
sr0 3:0:0:0 rom NECVMWar VMware SATA CD01 1.00 sata
现在让我们开始为已删除的物理卷恢复元数据。当使用 pvs,vgs,lvs 命令时,它将警告缺少 xxxxx UUID 的设备之一。
只需复制 UUID 并使用 grep 查看存档和备份。在进行重新引导之前,报告的 UUID 指的是 /dev/sdb 设备。
[root@localhost ~]# cat /etc/lvm/archive/vg_data_00002-1587647360.vg |grep -B 2 -A 9 "v6wYGZ-0dGA-8ecB-kec8-r2zv-gCJi-gulSAD"
pv1 {
id = "v6wYGZ-0dGA-8ecB-kec8-r2zv-gCJi-gulSAD"
device = "/dev/sdb" # Hint only
status = ["ALLOCATABLE"]
flags = []
dev_size = 41943040 # 20 Gigabytes
pe_start = 2048
pe_count = 5119 # 19.9961 Gigabytes
}
[root@localhost ~]# cat /etc/lvm/backup/vg_data |grep -B 2 -A 9 "v6wYGZ-0dGA-8ecB-kec8-r2zv-gCJi-gulSAD"
pv1 {
id = "v6wYGZ-0dGA-8ecB-kec8-r2zv-gCJi-gulSAD"
device = "/dev/sdb" # Hint only
status = ["ALLOCATABLE"]
flags = []
dev_size = 41943040 # 20 Gigabytes
pe_start = 2048
pe_count = 5119 # 19.9961 Gigabytes
}
让我们先使用 pvcreate --test
进行试运行:
[root@localhost ~]# pvcreate --test --uuid "v6wYGZ-0dGA-8ecB-kec8-r2zv-gCJi-gulSAD" --restorefile /etc/lvm/archive/vg_data_00002-1587647360.vg /dev/sdc
TEST MODE: Metadata will NOT be updated and volumes will not be (de)activated.
Couldn't find device with uuid l5rSrt-SRfc-KQNw-Tm29-gx4D-ihBw-Xzum3L.
Couldn't find device with uuid v6wYGZ-0dGA-8ecB-kec8-r2zv-gCJi-gulSAD.
Couldn't find device with uuid UYyDyH-vc6D-XbQ7-ga1X-DKeM-ObLe-tdBLxR.
Physical volume "/dev/sdc" successfully created.
- –test 试运行
- –uuid 用于指定新创建的物理卷的 uuid 值。如果没有此选项,将生成随机 UUID。在本实验中指定的 uuid 值是之前删除物理卷的 uuid 值。
- –restorefile 读取由 vgcfgbackup 生成的存档文件
去掉 --test
选项,正式创建物理卷:
[root@localhost ~]# pvcreate --uuid "v6wYGZ-0dGA-8ecB-kec8-r2zv-gCJi-gulSAD" --restorefile /etc/lvm/archive/vg_data_00002-1587647360.vg /dev/sdc
Couldn't find device with uuid l5rSrt-SRfc-KQNw-Tm29-gx4D-ihBw-Xzum3L.
Couldn't find device with uuid v6wYGZ-0dGA-8ecB-kec8-r2zv-gCJi-gulSAD.
Couldn't find device with uuid UYyDyH-vc6D-XbQ7-ga1X-DKeM-ObLe-tdBLxR.
Physical volume "/dev/sdc" successfully created.
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/nvme0n1p2 cl lvm2 a-- <19.00g <2.00g
/dev/sda vg_data lvm2 a-- <20.00g 0
/dev/sdb vg_data lvm2 a-- <20.00g 0
/dev/sdc vg_data lvm2 a-- <20.00g <9.99g
[root@localhost ~]# vgs
VG #PV #LV #SN Attr VSize VFree
cl 1 2 0 wz--n- <19.00g <2.00g
vg_data 3 2 0 wz--n- <59.99g <9.99g
[root@localhost ~]# lvs -o +devices
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert Devices
root cl -wi-ao---- 15.00g /dev/nvme0n1p2(512)
swap cl -wi-ao---- 2.00g /dev/nvme0n1p2(0)
lv_data vg_data -wi-a----- 25.00g /dev/sda(0)
lv_data vg_data -wi-a----- 25.00g /dev/sdc(0)
lv_log vg_data -wi-a----- 25.00g /dev/sdb(0)
lv_log vg_data -wi-a----- 25.00g /dev/sdc(1281)
然后使用 lvm 的备份还原卷组。首先加入 --test
试运行一下:
[root@localhost ~]# vgcfgrestore --test -f /etc/lvm/backup/vg_data vg_data
TEST MODE: Metadata will NOT be updated and volumes will not be (de)activated.
Volume group vg_data has active volume: lv_log.
Volume group vg_data has active volume: lv_data.
WARNING: Found 2 active volume(s) in volume group "vg_data".
Restoring VG with active LVs, may cause mismatch with its metadata.
Do you really want to proceed with restore of volume group "vg_data", while 2 volume(s) are active? [y/n]: y
Restored volume group vg_data.
下面正式运行一下,去掉 --test
选项:
[root@localhost ~]# vgcfgrestore -f /etc/lvm/backup/vg_data vg_data
Volume group vg_data has active volume: lv_log.
Volume group vg_data has active volume: lv_data.
WARNING: Found 2 active volume(s) in volume group "vg_data".
Restoring VG with active LVs, may cause mismatch with its metadata.
Do you really want to proceed with restore of volume group "vg_data", while 2 volume(s) are active? [y/n]: y
Restored volume group vg_data.
如果卷组和逻辑卷未激活,请使用下面命令激活:
# 扫描卷组
[root@localhost ~]# vgscan
Reading all physical volumes. This may take a while...
Found volume group "cl" using metadata type lvm2
Found volume group "vg_data" using metadata type lvm2
# 激活卷组 vg_data
[root@localhost ~]# vgchange -ay vg_data
2 logical volume(s) in volume group "vg_data" now active
# 扫描逻辑卷
[root@localhost ~]# lvscan
ACTIVE '/dev/cl/swap' [2.00 GiB] inherit
ACTIVE '/dev/cl/root' [15.00 GiB] inherit
ACTIVE '/dev/vg_data/lv_data' [25.00 GiB] inherit
ACTIVE '/dev/vg_data/lv_log' [25.00 GiB] inherit
在 lvm 中,需要执行一些步骤来恢复已删除的物理卷,方法是添加新磁盘并用现有 UUID 指向新磁盘。
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