Logical Volume Error: mount: special device /dev/mapper/DBBACKLOGS-archlogs1 does not exist

LVM Logical Volume Error: mount: special device /dev/mapper/DBBACKLOGS-archlogs1 does not exist

CentOS

After a storage issue when we got back the volumes, most of them were giving some strange errors. This one is one of such issue. The physical volume was visible in the system, however the Logical volume was not present. 

To fix the situation we need to do the following:






Option 1: 
Scan the Logical Volume. Check if it is active.

[root@thedbserver ~]# lvscan
  ACTIVE            '/dev/TORBCK/backup' [5.00 TiB] inherit
  ACTIVE            '/dev/DBBACKLOGS/archlogs1' [5.00 TiB] inherit
  
Try to activate the Logical Volume.

[root@thedbserver ~]# lvchange -ay -v /dev/DBBACKLOGS/archlogs1
    Using logical volume(s) on command line.
    Activating logical volume "archlogs1".
    activation/volume_list configuration setting not defined: Checking only host tags for DBBACKLOGS/archlogs1.

Check the Logical Volume status and try to mount the File system. 

[root@thedbserver ~]# lvs
  LV                 VG        Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  backup             TORBCK   -wi-ao----   5.00t
  archlogs1          DBBACKLOGS -wi-a-----   5.00t

[root@thedbserver ~]# mount -a
mount: special device /dev/mapper/DBBACKLOGS-archlogs1 does not exist



Option 2: 
Check the devices associated with logical volume.
[root@thedbserver ~]# lvs -a -o+devices
  LV                 VG        Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert Devices
  backup             TORBCK   -wi-ao----   5.00t                                                     /dev/mapper/STOR02-EXA2-BCK01(0
  archlogs1          DBBACKLOGS -wi-a-----   5.00t                                                     /dev/mapper/STOR03-EXA2-LOGS02(
  
 Check Logical volume output and check if open is 0 or 1. 

[root@thedbserver ~]# lvdisplay  /dev/DBBACKLOGS/archlogs1
  --- Logical volume ---
  LV Path                /dev/DBBACKLOGS/archlogs1
  LV Name                archlogs1
  VG Name                DBBACKLOGS
  LV UUID                
  LV Write Access        read/write
  LV Creation host, time thedbserver.local, 2016-05-02 21:05:40 +0200
  LV Status              available
  # open                 0
  LV Size                5.00 TiB
  Current LE             1310719
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           252:8

List out all the scsi devices.

[root@thedbserver ~]# lsscsi
[0:2:0:0]    disk    LSI      MR9361-8i        4.23  /dev/sda
[23:0:0:7]   disk    MSFT     STORSIMPLE 8600  222   /dev/sdb
[25:0:0:9]   disk    MSFT     STORSIMPLE 8100  222  /dev/sdc
[root@thedbserver ~]#

Now deactivate the logical volume.
[root@thedbserver ~]# lvchange -an DBBACKLOGS
[root@thedbserver ~]#

Check Logical Volume.

[root@thedbserver ~]# lvs
  LV                 VG        Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  backup             TORBCK   -wi-ao----   5.00t
  archlogs1          DBBACKLOGS -wi-------   5.00t
  
 Now Export the VG.

[root@thedbserver ~]# vgexport DBBACKLOGS
  Volume group "DBBACKLOGS" successfully exported
[root@thedbserver ~]#
[root@thedbserver ~]#

Check the VG's again.
[root@thedbserver ~]# vgs
  VG        #PV #LV #SN Attr   VSize VFree
  STORBCK     1   1   0 wz--n- 5.00t      0
  DBBACKLOGS   1   1   0 wzx-n- 5.00t      0
  VGExaDb     2   6   0 wz--n- 1.63t 788.08g
[root@thedbserver ~]#
[root@thedbserver ~]#

Now scan the vgs again.
[root@thedbserver ~]# vgscan
  Reading all physical volumes.  This may take a while...
  Found volume group "TORBCK" using metadata type lvm2
  Found exported volume group "DBBACKLOGS" using metadata type lvm2
  [root@thedbserver ~]# vgs
  VG        #PV #LV #SN Attr   VSize VFree
  TORBCK     1   1   0 wz--n- 5.00t      0
  DBBACKLOGS   1   1   0 wzx-n- 5.00t      0
  [root@thedbserver ~]#
[root@thedbserver ~]#

Now import the Concerned VG.
[root@thedbserver ~]# vgimport DBBACKLOGS
  Volume group "DBBACKLOGS" successfully imported
[root@thedbserver ~]#
[root@thedbserver ~]#

Check the VG's again.

[root@thedbserver ~]# vgs
  VG        #PV #LV #SN Attr   VSize VFree
  TORBCK     1   1   0 wz--n- 5.00t      0
  DBBACKLOGS   1   1   0 wz--n- 5.00t      0
 [root@thedbserver ~]#
[root@thedbserver ~]#

Now activate the Logical Volume.

[root@thedbserver ~]# lvchange -ay DBBACKLOGS

Now you can mount the File system.

[root@thedbserver ~]# mount -a