blkid can't find lvm's uuid

I created two LVM partitions, and can mount/use them. But when I try to mount it with UUID I get a message that says it can't find the UUID.

sudo lvdisplay
--- Logical volume ---
LV Path /dev/vg00/VolProject
LV Name VolProject
VG Name vg00
LV UUID HUhRED-ZUwG-cutq-fniL-1OOE-cZrd-ofoDZ3
LV Write Access read/write
LV Creation host, time ubuntu, 2017-04-04 18:41:55 -0700
LV Status available
# open 1
LV Size 17.00 GiB
Current LE 4351
Segments 3
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 252:0
--- Logical volume ---
LV Path /dev/vg00/volBackup
LV Name volBackup
VG Name vg00
LV UUID KZ6Y65-L9Qo-ShIz-pQ88-nIyD-P1n5-RGWcrw
LV Write Access read/write
LV Creation host, time ubuntu, 2017-04-04 18:42:42 -0700
LV Status available
# open 0
LV Size 6.99 GiB
Current LE 1790
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 252:1
ubuntu:/dev/vg00$ cat /etc/fstab
UUID=56b92ca1-312c-45e6-8f57-8c80762f96b9 / ext4 errors=remount-ro 0 1
UUID=07d0cb84-79a6-47bd-a155-cbfd045cf6ca none swap sw 0 0
/dev/fd0 /media/floppy0 auto rw,user,noauto,exec,utf8 0 0
#/dev/vg00/VolProject /home/davy/mnt auto defaults 0 0
UUID=HUhRED-ZUwG-cutq-fniL-1OOE-cZrd-ofoDZ3 /home/davy/mnt auto defaults 0 0
ubuntu:/dev/vg00$ blkid /dev/vg00/VolProject
ubuntu:/dev/vg00$ blkid /dev/vg00/volBackup

and when I do the mount -a:

ubuntu:/dev/vg00$ sudo mount -a
mount: can't find UUID=HUhRED-ZUwG-cutq-fniL-1OOE-cZrd-ofoDZ3

why is this happening? If I used the mount via /dev/vg00/VolProject it works, but if I use it's UUID it says that it can't find it. VG is created per instructions here:

1 Answer

Actually, you were confused between lvm UUID and block UUID.

The below command will display your lvm UUID, it point to specific item under lvm.

$ lvdisplay Logical-Volume

The below command will display your blcok UUID, it point to specific block device in your system.

$ blkid /dev/YOUR-Virtual-Group/YOUR-Logical-Volume

You should always use block UUID or device file instead of lvm UUID to modify the /etc/fstab record.