wipsfs 擦除磁盘签名后恢复分区

误操作使用 wipefs 命令清理的磁盘，ansible执行的没有以下返回值，如果有以下信息可以使用其他方法恢复

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wipefs -a -f /dev/sdb
/dev/sdb: 8 bytes were erased at offset 0x00000218 (LVM2_member): 4c 56 4d 32 20 30 30 31

执行 wipefs 后 pv 、vg、lvm 都没有了，但是分区挂载还在

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# pvs
# vgs
# lvs
# df -h
Filesystem                   Size  Used Avail Use% Mounted on
udev                         472M     0  472M   0% /dev
tmpfs                         98M  1.2M   97M   2% /run
/dev/sda1                    9.6G  1.7G  7.9G  18% /
tmpfs                        489M     0  489M   0% /dev/shm
tmpfs                        5.0M     0  5.0M   0% /run/lock
tmpfs                        489M     0  489M   0% /sys/fs/cgroup
/dev/loop0                    64M   64M     0 100% /snap/core20/1623
/dev/sda15                   105M  5.2M  100M   5% /boot/efi
/dev/mapper/datavg-lv_data1   10G  104M  9.9G   2% /data1
/dev/mapper/datavg-lv_data2  9.0G   97M  8.9G   2% /data2

取消 /etc/fstab 中的挂载，重启主机

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# cat /etc/fstab
LABEL=cloudimg-rootfs	/	 ext4	defaults	0 1
LABEL=UEFI	/boot/efi	vfat	umask=0077	0 1
#/dev/mapper/datavg-lv_data1 /data1 xfs defaults 0 0
#/dev/mapper/datavg-lv_data2 /data2 xfs defaults 0 0

# reboot

查看备份的 disk uuid，记录 pv0 的id

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# cat /etc/lvm/backup/datavg
# Generated by LVM2 version 2.03.07(2) (2019-11-30): Tue Nov 15 07:06:15 2022

contents = "Text Format Volume Group"
version = 1

description = "Created *after* executing 'vgs'"

creation_host = "ubuntuguest"	# Linux ubuntuguest 5.4.0-131-generic #147-Ubuntu SMP Fri Oct 14 17:07:22 UTC 2022 x86_64
creation_time = 1668495975	# Tue Nov 15 07:06:15 2022

datavg {
	id = "biPpie-lyHv-R7Og-u9OH-Z5S2-jVyp-hhZb5e"
	seqno = 7
	format = "lvm2"			# informational
	status = ["RESIZEABLE", "READ", "WRITE"]
	flags = []
	extent_size = 8192		# 4 Megabytes
	max_lv = 0
	max_pv = 0
	metadata_copies = 0

	physical_volumes {

		pv0 {
			id = "5rcocK-1vg0-fzR3-R2dW-ZbVO-eupP-fVf7sB"
			device = "/dev/sdb"	# Hint only

			status = ["ALLOCATABLE"]
			flags = []
			dev_size = 41943040	# 20 Gigabytes
			pe_start = 2048
			pe_count = 5119	# 19.9961 Gigabytes
		}
	}

	logical_volumes {

		lv_data1 {
			id = "OQ3Kqs-tdLh-0ooG-mhhO-wKVU-ekP2-SecDaA"
			status = ["READ", "WRITE", "VISIBLE"]
			flags = []
			creation_time = 1668167654	# 2022-11-11 11:54:14 +0000
			creation_host = "ubuntuguest"
			segment_count = 1

			segment1 {
				start_extent = 0
				extent_count = 2560	# 10 Gigabytes

				type = "striped"
				stripe_count = 1	# linear

				stripes = [
					"pv0", 0
				]
			}
		}

		lv_data2 {
			id = "sFNqz2-e0qH-we8k-p5t7-j8yt-d5oT-GWX2QF"
			status = ["READ", "WRITE", "VISIBLE"]
			flags = []
			creation_time = 1668167667	# 2022-11-11 11:54:27 +0000
			creation_host = "ubuntuguest"
			segment_count = 1

			segment1 {
				start_extent = 0
				extent_count = 2304	# 9 Gigabytes

				type = "striped"
				stripe_count = 1	# linear

				stripes = [
					"pv0", 2560
				]
			}
		}
	}

}

恢复 pv

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# /etc/lvm/backup/datavg 是最新的一次 datavg 的备份，历史备份位于 /etc/lvm/archive/
# pvcreate --uuid '5rcocK-1vg0-fzR3-R2dW-ZbVO-eupP-fVf7sB' --restorefile '/etc/lvm/backup/datavg' /dev/sdb
  WARNING: Couldn't find device with uuid 5rcocK-1vg0-fzR3-R2dW-ZbVO-eupP-fVf7sB.
  Physical volume "/dev/sdb" successfully created.

恢复vg

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# vgcfgrestore -f /etc/lvm/backup/datavg datavg
  Restored volume group datavg.

重启 lvm2-pvscan 服务

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# 多个 pv 可能有多个  lvm2-pvscan 服务，可以查看服务的日志确定其对应哪个 pv
systemctl restart lvm2-pvscan@8\\:16.service

取消 fstab 文件注释，重启挂载

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# cat /etc/fstab
LABEL=cloudimg-rootfs	/	 ext4	defaults	0 1
LABEL=UEFI	/boot/efi	vfat	umask=0077	0 1
/dev/mapper/datavg-lv_data1 /data1 xfs defaults 0 0
/dev/mapper/datavg-lv_data2 /data2 xfs defaults 0 0

# mount -a

验证，成功恢复pv，vg，lvm

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# pvs
  PV         VG     Fmt  Attr PSize   PFree
  /dev/sdb   datavg lvm2 a--  <20.00g 1020.00m

# vgs
  VG     #PV #LV #SN Attr   VSize   VFree
  datavg   1   2   0 wz--n- <20.00g 1020.00m

# lvs
  LV       VG     Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  lv_data1 datavg -wi-ao---- 10.00g
  lv_data2 datavg -wi-ao----  9.00g

# df -h
Filesystem                   Size  Used Avail Use% Mounted on
udev                         472M     0  472M   0% /dev
tmpfs                         98M  1.2M   97M   2% /run
/dev/sda1                    9.6G  1.7G  7.9G  18% /
/dev/loop0                    68M   68M     0 100% /snap/lxd/22753
/dev/sda15                   105M  5.2M  100M   5% /boot/efi
/dev/mapper/datavg-lv_data1   10G  104M  9.9G   2% /data1
/dev/mapper/datavg-lv_data2  9.0G   97M  8.9G   2% /data2