XenServer的断电导致系统崩溃而恢复数据的示例

由于 办公楼突然断电导致公司内部机房XenServer主机挂了一台，系统无法启动，宕机之前系统配置是
CPU：E5 2630 v3
内存：128GB
存储：3T 西数紫盘5块
阵列卡：LSI 9361-8i
磁盘采取了5块做raid5，当宕机无法启动之后，我采取了增加一块LSI9361-8i的卡和6块3T磁盘(硬件备件的重要性)，然后重新做了一组raid5，
在新的raid上重新安装了一个Xenserver系统，进入系统后我发现之前系统上的raid阵列没了分区表没了pv vg lv，突然之间我直接愣比了。。。

但是事情已经出了还是要想办法恢复的，首先要还原分区表，于是开始慢慢的爬坑和尝试了，这里不说走的弯路，直接说解决过程
首先查看当前系统的分区表详情。

[root@xenserver-DS-TestServer1 ~]# sgdisk -p /dev/sdb
Disk /dev/sdb: 29297213440 sectors, 13.6 TiB
Logical sector size: 512 bytes
Disk identifier (GUID): 96873AC9-0736-4EDD-B12C-9C64FA674119
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 29297213406
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)
 
Number  Start (sector)    End (sector)  Size       Code  Name
   1        46139392        83888127   18.0 GiB    0700 
   2         8390656        46139391   18.0 GiB    0700 
   3        87033856     29297213406   13.6 TiB    8E00 
   4        83888128        84936703   512.0 MiB   EF02 
   5            2048         8390655   4.0 GiB     0700 
   6        84936704        87033855   1024.0 MiB  8200 
[root@xenserver-DS-TestServer1 ~]#

然后发现，XenServer非常好的动作就是数据存储分区虽然ID不是最后一个但是分区的块是最后一个，那么喜讯来了，我们完全可以借助现有的分区信息恢复之前的分表。

[root@xenserver-DS-TestServer1 ~]# sgdisk -p --new=5:2048:8390655 -t 5:0700 /dev/sda
[root@xenserver-DS-TestServer1 ~]# sgdisk -p --new=2:8390656:46139391 -t 2:0700 /dev/sda
[root@xenserver-DS-TestServer1 ~]# sgdisk -p --new=1:46139392:83888127 -t 1:0700 /dev/sda
[root@xenserver-DS-TestServer1 ~]# sgdisk -p --new=4:83888128:84936703 -t 4:EF02 /dev/sda
[root@xenserver-DS-TestServer1 ~]# sgdisk -p --new=6:84936704:87033855 -t 6:8200 /dev/sda
[root@xenserver-DS-TestServer1 ~]# sgdisk -p --new=3:87033856 -t 3:8E00 /dev/sda
命令解释 由于是大于2T的磁盘做分区所以需要用他来做GPT分区
-p 是打印信息用的
--new=X:起始位置:结束位置 (没有结束位置就是到最后)
-t X:分区类型代码
来看看恢复的分区表是不是正确的

[root@xenserver-DS-TestServer1 ~]# sgdisk -p /dev/sda
Disk /dev/sda: 23437770752 sectors, 10.9 TiB
Logical sector size: 512 bytes
Disk identifier (GUID): 589962FD-858D-4789-A026-E08AD53863FF
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 23437770718
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)
 
Number  Start (sector)    End (sector)  Size       Code  Name
   1        46139392        83888127   18.0 GiB    0700 
   2         8390656        46139391   18.0 GiB    0700 
   3        87033856     23437770718   10.9 TiB    8E00 
   4        83888128        84936703   512.0 MiB   EF02 
   5            2048         8390655   4.0 GiB     0700 
   6        84936704        87033855   1024.0 MiB  8200 
[root@xenserver-DS-TestServer1 ~]# mkdir /1
[root@xenserver-DS-TestServer1 ~]# mount /dev/sda1 /1
[root@xenserver-DS-TestServer1 ~]# ls /1
1  bin  boot  cli-rt  dev  etc  EULA  home  iso_storage  lib  lib64  lost+found  media  mnt  opt  proc  Read_Me_First.html  root  run  sbin  srv  sys  tmp  usr  var

分区表回来了，现在就是要做恢复pv了,由于XenServer在/etc/lvm/backup/下有存放lvm的备份信息，所以直接来操作

[root@xenserver-DS-TestServer1 ~]# ls /etc/lvm/backup/
VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59  XSLocalEXT-0d4b3188-1afd-ecf7-44a4-2d594d966b35
[root@xenserver-DS-TestServer1 ~]# grep -A1 pv0 /etc/lvm/backup/VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 |head -3 #取之前PV的ID
                pv0 {
                        id = "XBPMJ4-QTR0-I76k-32jy-UiKR-EaOh-gDu954"
--
[root@xenserver-DS-TestServer1 ~]# pvcreate /dev/sda3 \
-u XBPMJ4-QTR0-I76k-32jy-UiKR-EaOh-gDu954 --restorefile \
/etc/lvm/backup/VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59
[root@xenserver-DS-TestServer1 ~]# vgcfgrestore
[root@xenserver-DS-TestServer1 ~]# pvs
  PV         VG                                                 Fmt  Attr PSize  PFree
  /dev/sda3  VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 lvm2 a--  10.87t 8.34t
  /dev/sdb3  XSLocalEXT-0d4b3188-1afd-ecf7-44a4-2d594d966b35    lvm2 a--  13.60t    0
[root@xenserver-DS-TestServer1 ~]# vgs
  VG                                                 #PV #LV #SN Attr   VSize  VFree
  VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59   1  19   0 wz--n- 10.87t 8.34t
  XSLocalEXT-0d4b3188-1afd-ecf7-44a4-2d594d966b35      1   1   0 wz--n- 13.60t    0
[root@xenserver-DS-TestServer1 ~]# lvs
  LV                                       VG                                                 Attr       LSize    Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  MGT                                      VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-a-----    4.00m                                                   
  VHD-0dcf2cc7-1065-41db-9e23-148a417fe217 VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -ri-------    9.71g                                                   
  VHD-0f475f75-96e6-40c3-949b-434952569d20 VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-------   15.04g                                                   
  VHD-18b5ed2b-7c53-43cb-b5f6-6cd7150818fc VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-------   40.09g                                                   
  VHD-514a4efe-3b67-419b-a5b4-117758b1bb0b VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -ri-------    2.05g                                                   
  VHD-52ab4b8e-c2cb-409d-b0cd-2d7d3e83d406 VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-ao----    8.00m                                                   
  VHD-5448d7b8-2d34-4c11-8239-cc73cc2c5fcf VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-------  100.20g                                                   
  VHD-68c7616e-2255-4b7d-b466-ceff675c3dac VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-------   40.09g                                                   
  VHD-70430d5b-81d7-4ef5-97d1-b469ffc68329 VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi------- 1001.96g                                                   
  VHD-ba7fdf40-8949-49e8-9a8d-3cd82e681d05 VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-------   15.04g                                                   
  VHD-c2489598-8c15-46a8-875d-de330c3a3d45 VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-------   15.04g                                                   
  VHD-c9765741-c451-4a58-b90a-b14529b5037b VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-------   15.04g                                                   
  VHD-d5bf4179-b9e5-4286-a94d-88c42cb803c4 VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-------  100.20g                                                   
  VHD-db9b028f-9490-40cb-9d14-3099753db6e3 VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -ri-ao----  108.68g                                                   
  VHD-de709c9b-12c0-4854-a98d-79868b4a2c2e VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-ao----  751.47g                                                   
  VHD-e89b9b3d-cc07-456e-bcd0-7630c5d41224 VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-------  200.40g                                                   
  VHD-f680824c-d00a-4233-bbdc-6b935930b5ab VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-------   40.09g                                                   
  VHD-fcc379ee-b7cb-4b47-b349-4fea5b1b75b5 VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-ao----  120.24g                                                   
  local_iso                                VG_XenStorage-275f0172-dec8-aa20-81a5-5e50cd637f59 -wi-a-----   20.00g                                                   
  0d4b3188-1afd-ecf7-44a4-2d594d966b35     XSLocalEXT-0d4b3188-1afd-ecf7-44a4-2d594d966b35    -wi-ao----   13.60t                                                   
[root@xenserver-DS-TestServer1 ~]#

到了这是分区信息都回来，但是这才是开始，最重要的是群让真实数据能不能回来，继续

[root@xenserver-DS-TestServer1 ~]# cat /proc/partitions
major minor  #blocks  name
 
   7        0      56104 loop0
   8        0 11718885376 sda
   8        1   18874368 sda1
   8        2   18874368 sda2
   8        3 11675368431 sda3
   8        4     524288 sda4
   8        5    4194304 sda5
   8        6    1048576 sda6
   8       16 14648606720 sdb
   8       17   18874368 sdb1
   8       18   18874368 sdb2
   8       19 14605089775 sdb3
   8       20     524288 sdb4
   8       21    4194304 sdb5
   8       22    1048576 sdb6
 253       15   20971520 dm-15
 253        0 14605074432 dm-0
 253        1       4096 dm-1
 253        2  787976192 dm-2
 254        0  786432000 tda
 253        4  113958912 dm-4
 254        4  125829120 tde
 253        8  126083072 dm-8
 253       11       8192 dm-11
 254        6  125829120 tdg
[root@xenserver-DS-TestServer1 ~]# ls -l /dev/disk/by-id/
total 0
lrwxrwxrwx 1 root root 11 Aug  8 03:58 dm-name-VG_XenStorage--275f0172--dec8--aa20--81a5--5e50cd637f59-local_iso -> ../../dm-15
lrwxrwxrwx 1 root root 10 Aug  8 04:10 dm-name-VG_XenStorage--275f0172--dec8--aa20--81a5--5e50cd637f59-MGT -> ../../dm-1
lrwxrwxrwx 1 root root 11 Aug  8 06:35 dm-name-VG_XenStorage--275f0172--dec8--aa20--81a5--5e50cd637f59-VHD--52ab4b8e--c2cb--409d--b0cd--2d7d3e83d406 -> ../../dm-11
lrwxrwxrwx 1 root root 10 Aug  8 06:35 dm-name-VG_XenStorage--275f0172--dec8--aa20--81a5--5e50cd637f59-VHD--db9b028f--9490--40cb--9d14--3099753db6e3 -> ../../dm-4
lrwxrwxrwx 1 root root 10 Aug  8 06:30 dm-name-VG_XenStorage--275f0172--dec8--aa20--81a5--5e50cd637f59-VHD--de709c9b--12c0--4854--a98d--79868b4a2c2e -> ../../dm-2
lrwxrwxrwx 1 root root 10 Aug  8 06:35 dm-name-VG_XenStorage--275f0172--dec8--aa20--81a5--5e50cd637f59-VHD--fcc379ee--b7cb--4b47--b349--4fea5b1b75b5 -> ../../dm-8
lrwxrwxrwx 1 root root 10 Aug  8 04:08 dm-name-XSLocalEXT--0d4b3188--1afd--ecf7--44a4--2d594d966b35-0d4b3188--1afd--ecf7--44a4--2d594d966b35 -> ../../dm-0
lrwxrwxrwx 1 root root 10 Aug  8 06:35 dm-uuid-LVM-cB4XlG6peENnKKsK5GMqts3eoYCo0OQE54qZ1ihUCdsQzGv4IX8yRhLQS6iOazUu -> ../../dm-8
lrwxrwxrwx 1 root root 10 Aug  8 06:30 dm-uuid-LVM-cB4XlG6peENnKKsK5GMqts3eoYCo0OQE9ojbv4bKtZGXEtePHxe1o7N6t40c89hL -> ../../dm-2
lrwxrwxrwx 1 root root 10 Aug  8 04:10 dm-uuid-LVM-cB4XlG6peENnKKsK5GMqts3eoYCo0OQEG8pbhDHsVhGuXyTCKXzBj52T75eI0nS6 -> ../../dm-1
lrwxrwxrwx 1 root root 11 Aug  8 06:35 dm-uuid-LVM-cB4XlG6peENnKKsK5GMqts3eoYCo0OQEICcxLBeQZj1kSExK2tpMvybRiFWUPy21 -> ../../dm-11
lrwxrwxrwx 1 root root 11 Aug  8 03:58 dm-uuid-LVM-cB4XlG6peENnKKsK5GMqts3eoYCo0OQErJH0l0NRX7RcgMcnOioxqcDsLklo2fD3 -> ../../dm-15
lrwxrwxrwx 1 root root 10 Aug  8 06:35 dm-uuid-LVM-cB4XlG6peENnKKsK5GMqts3eoYCo0OQEUAvD8Ndo1on9yX3bfOxn16ijjssrsYYI -> ../../dm-4
lrwxrwxrwx 1 root root 10 Aug  8 04:08 dm-uuid-LVM-TGxgVKcz2NC899CJrQrB6qV55Uyc5kR2TDTlQyso0Ww4ymeZIVeCpmi7uuWpFa85 -> ../../dm-0
lrwxrwxrwx 1 root root  9 Aug  8 06:24 scsi-3600605b000b393401f3a02470682c385 -> ../../sdb
lrwxrwxrwx 1 root root 10 Aug  8 06:24 scsi-3600605b000b393401f3a02470682c385-part1 -> ../../sdb1
lrwxrwxrwx 1 root root 10 Aug  8 06:24 scsi-3600605b000b393401f3a02470682c385-part2 -> ../../sdb2
lrwxrwxrwx 1 root root 10 Aug  8 06:24 scsi-3600605b000b393401f3a02470682c385-part3 -> ../../sdb3
lrwxrwxrwx 1 root root 10 Aug  8 06:24 scsi-3600605b000b393401f3a02470682c385-part4 -> ../../sdb4
lrwxrwxrwx 1 root root 10 Aug  8 06:24 scsi-3600605b000b393401f3a02470682c385-part5 -> ../../sdb5
lrwxrwxrwx 1 root root 10 Aug  8 06:24 scsi-3600605b000b393401f3a02470682c385-part6 -> ../../sdb6
lrwxrwxrwx 1 root root  9 Aug  8 06:42 scsi-3600605b000b394e01f20a4c6273ed3e2 -> ../../sda
lrwxrwxrwx 1 root root 10 Aug  8 06:42 scsi-3600605b000b394e01f20a4c6273ed3e2-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 Aug  8 06:42 scsi-3600605b000b394e01f20a4c6273ed3e2-part2 -> ../../sda2
lrwxrwxrwx 1 root root 10 Aug  8 06:42 scsi-3600605b000b394e01f20a4c6273ed3e2-part3 -> ../../sda3
lrwxrwxrwx 1 root root 10 Aug  8 06:42 scsi-3600605b000b394e01f20a4c6273ed3e2-part4 -> ../../sda4
lrwxrwxrwx 1 root root 10 Aug  8 06:42 scsi-3600605b000b394e01f20a4c6273ed3e2-part5 -> ../../sda5
lrwxrwxrwx 1 root root 10 Aug  8 06:42 scsi-3600605b000b394e01f20a4c6273ed3e2-part6 -> ../../sda6
lrwxrwxrwx 1 root root  9 Aug  8 06:24 wwn-0x600605b000b393401f3a02470682c385 -> ../../sdb
lrwxrwxrwx 1 root root 10 Aug  8 06:24 wwn-0x600605b000b393401f3a02470682c385-part1 -> ../../sdb1
lrwxrwxrwx 1 root root 10 Aug  8 06:24 wwn-0x600605b000b393401f3a02470682c385-part2 -> ../../sdb2
lrwxrwxrwx 1 root root 10 Aug  8 06:24 wwn-0x600605b000b393401f3a02470682c385-part3 -> ../../sdb3
lrwxrwxrwx 1 root root 10 Aug  8 06:24 wwn-0x600605b000b393401f3a02470682c385-part4 -> ../../sdb4
lrwxrwxrwx 1 root root 10 Aug  8 06:24 wwn-0x600605b000b393401f3a02470682c385-part5 -> ../../sdb5
lrwxrwxrwx 1 root root 10 Aug  8 06:24 wwn-0x600605b000b393401f3a02470682c385-part6 -> ../../sdb6
lrwxrwxrwx 1 root root  9 Aug  8 06:42 wwn-0x600605b000b394e01f20a4c6273ed3e2 -> ../../sda
lrwxrwxrwx 1 root root 10 Aug  8 06:42 wwn-0x600605b000b394e01f20a4c6273ed3e2-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 Aug  8 06:42 wwn-0x600605b000b394e01f20a4c6273ed3e2-part2 -> ../../sda2
lrwxrwxrwx 1 root root 10 Aug  8 06:42 wwn-0x600605b000b394e01f20a4c6273ed3e2-part3 -> ../../sda3
lrwxrwxrwx 1 root root 10 Aug  8 06:42 wwn-0x600605b000b394e01f20a4c6273ed3e2-part4 -> ../../sda4
lrwxrwxrwx 1 root root 10 Aug  8 06:42 wwn-0x600605b000b394e01f20a4c6273ed3e2-part5 -> ../../sda5
lrwxrwxrwx 1 root root 10 Aug  8 06:42 wwn-0x600605b000b394e01f20a4c6273ed3e2-part6 -> ../../sda6
[root@xenserver-DS-TestServer1 ~]#

[root@xenserver-DS-TestServer1 ~]# xe host-list
uuid ( RO)                : 3da0c2a0-e4c5-44ba-bb20-77a2b51198e3
          name-label ( RW): xenserver-DS-TestServer1
    name-description ( RW): Default install
 
 
[root@xenserver-DS-TestServer1 ~]#
 
[root@xenserver-DS-TestServer1 ~]# xe sr-create content-type=user \
device-config:device=/dev/disk/by-id/wwn-0x600605b000b394e01f20a4c6273ed3e2-part3 \
host-uuid=3da0c2a0-e4c5-44ba-bb20-77a2b51198e3 name-label="Local storage 2" shared=false type=lvm
这时候惊喜的发现之前的vm分区都回来，但是也有不完美的地方，如下图