How do you create LVM snapshot after the error message "not found: device not cleared"

I'm trying to test LVM, but I failed on first, potentially simple task - create a snapshot.

I have following situation:

root@debian:~# vgs
  VG   #PV #LV #SN Attr   VSize  VFree
  big    1   1   0 wz--n- 14.99g 5.68g
  fast   1   2   0 wz--n- 14.99g 4.75g

and

root@debian:~# lvs
  Internal error: Using string as sort value for numerical field.
  Internal error: Using string as sort value for numerical field.
  Internal error: Using string as sort value for numerical field.
  LV   VG   Attr     LSize   Pool Origin Data%  Move Log Copy%  Convert
  home big  -wi-ao--   9.31g                                           
  root fast -wi-ao--   9.31g                                           
  swap fast -wi-ao-- 952.00m

I'd like to make test snapshot of home, so Figured this will be the command to use:

lvcreate --size 1G -n snap -s /dev/big/home

But it fails with:

/dev/big/snap: not found: device not cleared
Aborting. Failed to wipe snapshot exception store.

Well, obviously there is no /dev/big/snap - I didn't make the snapshot yet.

/dev/big contains only link to home:

root@debian:~# ls -l /dev/big/
total 0
lrwxrwxrwx 1 root root 7 Nov 28 18:09 home -> ../dm-2

What am I missing in here?

Your lvcreate command looks fine. One thing that will cause this error is if udev isn't running. Try service udev status to see if it's running, and service udev start if it's not.

This happened to me during a dist-upgrade from Debian 7 Wheezy to Debian 8 Jessie, too, where the udev package was already upgraded, but the lvm2 wasn't yet. Upgrading the lvm2 package helped and the lvmcreate command worked fine again.

How do you create LVM snapshot after the error message "not found: device not cleared"

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