Description of problem:
While users can use thin-pool with lots of thin LVs - there can be cases, where user may prefer to 'drop' some volumes to make space for other more important ones. This is fine as long as 'low-prio' thin volumes are not use - but it's getting complicated for the case volumes is in use 'somewhere'.
The possible take on lvm2 side could be - to migrate such LV (no just thin) to a single segmented 'error' LV - which den gives thin-pool change to drop conntent of such thinLV.
Once the 'error' LV gets unused - it can be easily lvremoved - either later by user or some monitoring process (lvmpolld) - or any later 'lvcreate/lvconvert' my check & drop such LV appropriately flagged.
In practical implementation this is equivalent of using:
'dmsetup remove --force'.
Naive assumptions to be explored is - the reaction of mounted filesystem replaced with error device - in most cases I'd expect the filesystem will not kill the system - just stops itself... but this needs to be validated...
As for users's API - ideas may range from adding flag option to even extra command...
'lvremove --force --atleastreplacewitherror vg/lv'
Version-Release number of selected component (if applicable):
Steps to Reproduce:
I guess the inital good progress can be achieve with support for:
'lvconvert --type error|zero'
this can may simplify number of recovery operations.
This operation might be even support for VG with missing PV - as it does not present problem for PV allocation - and in practice it five lower-lever control for this case.