RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Was trying to test the 'lvconvert --uncache' feature.  I created a cache LV and killed the device under the cache-pool.  After that, no LVM command would work.

[root@bp-01 ~]# lvs -a -o name,size,attr,devices vg
  LV                LSize   Attr       Devices
  [cachepool]         5.00g Cwi---C--- cachepool_cdata(0)
  [cachepool_cdata]   5.00g Cwi-ao---- /dev/sdb1(128004)
  [cachepool_cmeta]   8.00m ewi-ao---- /dev/sdb1(128002)
  lv                500.00g Cwi-a-C--- lv_corig(0)
  [lv_corig]        500.00g owi-aoC--- /dev/sdb1(0)
  [lvol0_pmspare]     8.00m ewi------- /dev/sdb1(128000)

I use the following command to disable the cache device (/dev/sdb1):
# echo offline > /sys/block/$dev/device/state

I will upload the 'vvvv' trace I got after attempting 'lvconvert --uncache' at this point.

Created attachment 1204883 [details]
Output from hung 'lvconvert --uncache vg/lv -vvvv'

I stupidly allowed the origin and cachepool to be created on the same PV in the earlier example.  Here it is again after putting them on separate devices:

[root@bp-01 ~]# !lvs
lvs -a -o name,size,attr,devices vg
  LV                LSize   Attr       Devices
  [cachepool]         5.00g Cwi---C--- cachepool_cdata(0)
  [cachepool_cdata]   5.00g Cwi-ao---- /dev/sdc1(4)
  [cachepool_cmeta]   8.00m ewi-ao---- /dev/sdc1(2)
  lv                500.00g Cwi-a-C--- lv_corig(0)
  [lv_corig]        500.00g owi-aoC--- /dev/sdb1(0)
  [lvol0_pmspare]     8.00m ewi------- /dev/sdc1(0)
[root@bp-01 ~]# off.sh /dev/sdc1
Turning off sdc

Created attachment 1204891 [details]
Output from hung 'lvconvert --uncache vg/lv -vvvv'

Created attachment 1204945 [details]
Backtrace of the stuck process (stuck on suspend ioctl)

*** This bug has been marked as a duplicate of bug 1377850 ***