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Disk disappeared after umount and reboot

cn flag

I had a disk which disappeared:

# df -h
Filesystem                    Size  Used Avail Use% Mounted on
.
.
/dev/mapper/vg1-osblv02       5.0T   61G  4.7T   2% /data/osb-pool-1
/dev/mapper/vg01-osblv01      1.8T   45G  1.7T   3% /data/osb-pool-0
 .
 .     

but after I did a force umount on dev/mapper/vg1-osblv02 and rebooted I could not see it any longer:


# df -h
Filesystem                    Size  Used Avail Use% Mounted on
 .
 .
 .
#

so after reboot I can not see it some more information on this:

# lsblk
NAME                 MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sdb                    8:16   0    5T  0 disk
└─sdb1                 8:17   0    5T  0 part
  └─vg1-osblv02      252:7    0    5T  0 lvm
vg0-osblv01          252:6    0  1.8T  0 lvm
osb_pool-lvol001     252:4    0  1.8T  0 lvm
sr0                   11:0    1  4.3G  0 rom
xvdb                 202:16   0  300G  0 disk
├─xvdb2              202:18   0  299G  0 part
│ ├─ol_hohfcosb-swap 252:1    0   24G  0 lvm  [SWAP]
│ ├─ol_hohfcosb-var  252:2    0   20G  0 lvm  /var
│ ├─ol_hohfcosb-root 252:0    0  239G  0 lvm  /
│ └─ol_hohfcosb-tmp  252:3    0   16G  0 lvm  /tmp
└─xvdb1              202:17   0    1G  0 part /boot
sda                    8:0    0  1.8T  0 disk
└─sda1                 8:1    0  1.8T  0 part
  └─vg01-osblv01     252:8    0  1.8T  0 lvm  /data/osb-pool-0
osb_pool_1-lvol001   252:5    0    5T  0 lvm

After reboot:

# lsblk
NAME                 MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sr0                   11:0    1  4.3G  0 rom
xvdb                 202:16   0  300G  0 disk
├─xvdb2              202:18   0  299G  0 part
│ ├─ol_hohfcosb-swap 252:1    0   24G  0 lvm  [SWAP]
│ ├─ol_hohfcosb-var  252:2    0   20G  0 lvm  /var
│ ├─ol_hohfcosb-root 252:0    0  239G  0 lvm  /
│ └─ol_hohfcosb-tmp  252:3    0   16G  0 lvm  /tmp
└─xvdb1              202:17   0    1G  0 part /boot
sda                    8:0    0  500G  0 disk

when I checked the /etc/fstab I got this:

# /etc/fstab
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/ol_hohfcosb-root /                       xfs     defaults        0 0
UUID=57d32b2b-89bb-42e3-8a49-3f5c2d1ab1b6 /boot                   xfs     defaults        0 0
/dev/mapper/ol_hohfcosb-tmp /tmp                    xfs     defaults        0 0
/dev/mapper/ol_hohfcosb-var /var                    xfs     defaults        0 0
/dev/mapper/ol_hohfcosb-swap swap                    swap    defaults        0 0
/dev/mapper/vg1-osblv02 /data/osb-pool-1            ext4     defaults              0 0
/dev/mapper/vg01-osblv01 /data/osb-pool-0       ext4    defaults        0 0

pvs

# pvs
  PV         VG          Fmt  Attr PSize    PFree
  /dev/xvdb2 ol_hohfcosb lvm2 a--  <299.00g 4.00m

vgs

# vgs
  VG          #PV #LV #SN Attr   VSize    VFree
  ol_hohfcosb   1   4   0 wz--n- <299.00g 4.00m

lvs

# lvs
  LV   VG          Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root ol_hohfcosb -wi-ao---- 238.99g
  swap ol_hohfcosb -wi-ao----  24.00g
  tmp  ol_hohfcosb -wi-ao----  16.00g
  var  ol_hohfcosb -wi-ao----  20.00g
#
cn flag
Can you manually mount the filesystems? Add the contents of `/etc/fstab` to your question.
kunz avatar
cn flag
@NasirRiley how would i go about doing that help please
kunz avatar
cn flag
@NasirRiley i updated my question with the fstab content
cn flag
Use the command `mount -a` and add the output to the question.
kunz avatar
cn flag
@NasirRiley i get this error `mount: special device /dev/mapper/vg1-osblv02 does not exist`
cn flag
I should have asked this before, but add the output of `pvs`, `vgs`, and `lvs` to your question.
kunz avatar
cn flag
@NasirRiley i have added the output
kunz avatar
cn flag
Let us [continue this discussion in chat](https://chat.stackexchange.com/rooms/129113/discussion-between-kunz-and-nasir-riley).
George Shuklin avatar
cn flag
It looks like you've lost some block devices. Did you use some non-persistent volumes? iscsi, etc?
kunz avatar
cn flag
@GeorgeShuklin i am not sure its a pre build machine and am just a new person working on it :( sadly am lost
George Shuklin avatar
cn flag
Basically, there are two options: 1) There is no disk inside VM (because it was ephimerial, or is not automatically attached to VM at start) 2) `pvscan` can't find a local pv. I'd start from inventorizing all block devices on server to see if there are any unused. If not, I'd go to virt guys for help/logs/etc.
Michael Hampton avatar
cz flag
What happened to your disks sda and sdb?
cptMikky avatar
us flag
sdb disappeared - your problem is way deeper than filesystem or lvm. Check `dmesg` for errors. Also if this is some kind of a VM the disk may have been ephemeral as George said so your best bet is to go check the host whether the backing device/image is still there.
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