What were you trying to do that didn't work?

This is a regression test that we run to swap in a repaired _tmeta device for corrupted thin pools. It started failing with the latest d-m-p-d.

# OLD: device-mapper-persistent-data-0.9.0-13.el9    BUILT: Wed Jun 22 06:27:41 PM CEST 2022

[root@virt-506 ~]# lvcreate -yes  -thinpool POOL -L 1G --zero y --poolmetadataspare n snapper_thinp
 Thin pool volume with chunk size 64.00 KiB can address at most <15.88 TiB of data.
 WARNING: recovery of pools without pool metadata spare LV is not automated.
 Logical volume "POOL" created.
[root@virt-506 ~]# lvcreate -yes  -virtualsize 250M -T snapper_thinp/POOL -n other1
 Rounding up size to full physical extent 252.00 MiB
 Logical volume "other1" created.
[root@virt-506 ~]# lvcreate --yes  -V 250M -T snapper_thinp/POOL -n other2
 Rounding up size to full physical extent 252.00 MiB
 Logical volume "other2" created.
[root@virt-506 ~]# lvs -a -o +devices
 LV           VG            Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert Devices        
 root         rhel_virt-506 wi-ao---  <6.20g                                                     /dev/vda2(205)
 swap         rhel_virt-506 wi-ao--- 820.00m                                                     /dev/vda2(0)   
 POOL         snapper_thinp twi-aotz--   1.00g             0.00   11.13                            POOL_tdata(0)  
 [POOL_tdata] snapper_thinp Twi-ao----   1.00g                                                     /dev/sda1(0)   
 [POOL_tmeta] snapper_thinp ewi-ao----   4.00m                                                     /dev/sdh1(0)   
 other1       snapper_thinp Vwi-a-tz-- 252.00m POOL        0.00                                                   
 other2       snapper_thinp Vwi-a-tz-- 252.00m POOL        0.00                                                   
[root@virt-506 ~]# dd if=/dev/urandom of=/dev/mapper/snapper_thinp-POOL_tmeta count=512 seek=4096 bs=1
512+0 records in
512+0 records out
512 bytes copied, 0.00141767 s, 361 kB/s
[root@virt-506 ~]# lvchange -an --yes --select 'lv_name=POOL || pool_lv=POOL'
[root@virt-506 ~]# lvcreate --yes  -L 4M -n meta_swap.269 snapper_thinp
 Logical volume "meta_swap.269" created.
[root@virt-506 ~]# lvconvert --yes --thinpool snapper_thinp/POOL --poolmetadata snapper_thinp/meta_swap.269
[root@virt-506 ~]# lvchange -ay snapper_thinp/meta_swap.269
[root@virt-506 ~]# thin_check /dev/mapper/snapper_thinp-meta_swap.269
examining superblock
TRANSACTION_ID=2
METADATA_FREE_BLOCKS=1023
examining devices tree
examining mapping tree
 thin device 1 is missing mappings [0, -]
   bad checksum in btree node (block 1)
[root@virt-506 ~]# lvchange -an snapper_thinp/meta_swap.269
[root@virt-506 ~]# lvconvert --yes --thinpool snapper_thinp/POOL --poolmetadata snapper_thinp/meta_swap.269
[root@virt-506 ~]# lvremove -f snapper_thinp/meta_swap.269
 Logical volume "meta_swap.269" successfully removed.
[root@virt-506 ~]# lvchange -ay --yes --select 'lv_name=POOL || pool_lv=POOL'
 Check of pool snapper_thinp/POOL failed (status:1). Manual repair required!
[root@virt-506 ~]# lvconvert --yes --repair snapper_thinp/POOL /dev/sdb1
 WARNING: LV snapper_thinp/POOL_meta0 holds a backup of the unrepaired metadata. Use lvremove when no longer required.
 WARNING: New metadata LV snapper_thinp/POOL_tmeta might use different PVs.  Move it with pvmove if required.
[root@virt-506 ~]# lvs -a -o +devices
 LV              VG            Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert Devices        
 root            rhel_virt-506 wi-ao---  <6.20g                                                     /dev/vda2(205)
 swap            rhel_virt-506 wi-ao--- 820.00m                                                     /dev/vda2(0)   
 POOL            snapper_thinp twi--tz-   1.00g                                                     POOL_tdata(0)  
 POOL_meta0      snapper_thinp wi------   4.00m                                                     /dev/sdh1(0)   
 [POOL_tdata]    snapper_thinp Twi-------   1.00g                                                     /dev/sda1(0)   
 [POOL_tmeta]    snapper_thinp ewi-------   4.00m                                                     /dev/sdb1(0)   
 [lvol1_pmspare] snapper_thinp ewi-------   4.00m                                                     /dev/sdb1(1)   
 other1          snapper_thinp Vwi--tz- 252.00m POOL                                                               
 other2          snapper_thinp Vwi--tz- 252.00m POOL                                                               

1. NEW: device-mapper-persistent-data-1.0.6-1.el9    BUILT: Fri Aug 11 10:13:30 AM EDT 2023

[root@megatest-11 ~]# lvcreate -yes  -thinpool POOL -L 1G --zero y --poolmetadataspare n snapper_thinp
 Thin pool volume with chunk size 64.00 KiB can address at most <15.88 TiB of data.
 WARNING: recovery of pools without pool metadata spare LV is not automated.
 Logical volume "POOL" created.
[root@megatest-11 ~]# lvcreate -yes  -virtualsize 250M -T snapper_thinp/POOL -n other1
 Rounding up size to full physical extent 252.00 MiB
 Logical volume "other1" created.
[root@megatest-11 ~]# lvcreate --yes  -V 250M -T snapper_thinp/POOL -n other2
 Rounding up size to full physical extent 252.00 MiB
 Logical volume "other2" created.
[root@megatest-11 ~]# lvs -a -o +devices
 LV           VG               Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert Devices        
 root         rhel_megatest-11 wi-ao---  <6.20g                                                     /dev/vda2(205)
 swap         rhel_megatest-11 wi-ao--- 820.00m                                                     /dev/vda2(0)   
 POOL         snapper_thinp    twi-aotz--   1.00g             0.00   11.13                            POOL_tdata(0)  
 [POOL_tdata] snapper_thinp    Twi-ao----   1.00g                                                     /dev/sdd1(0)   
 [POOL_tmeta] snapper_thinp    ewi-ao----   4.00m                                                     /dev/sda1(0)   
 other1       snapper_thinp    Vwi-a-tz-- 252.00m POOL        0.00                                                   
 other2       snapper_thinp    Vwi-a-tz-- 252.00m POOL        0.00                                                   
[root@megatest-11 ~]# dd if=/dev/urandom of=/dev/mapper/snapper_thinp-POOL_tmeta count=512 seek=4096 bs=1
512+0 records in
512+0 records out
512 bytes copied, 0.00284311 s, 180 kB/s
[root@megatest-11 ~]# lvchange -an --yes --select 'lv_name=POOL || pool_lv=POOL'
[root@megatest-11 ~]# lvcreate --yes  -L 4M -n meta_swap.269 snapper_thinp
 Logical volume "meta_swap.269" created.
[root@megatest-11 ~]# lvconvert --yes --thinpool snapper_thinp/POOL --poolmetadata snapper_thinp/meta_swap.269
[root@megatest-11 ~]# lvchange -ay snapper_thinp/meta_swap.269
[root@megatest-11 ~]# thin_check /dev/mapper/snapper_thinp-meta_swap.269
TRANSACTION_ID=2
METADATA_FREE_BLOCKS=1012
Thin device 1 is missing root with 0 mappings
Check of mappings failed
[root@megatest-11 ~]# echo $?
64
[root@megatest-11 ~]# lvchange -an snapper_thinp/meta_swap.269
[root@megatest-11 ~]# lvconvert --yes --thinpool snapper_thinp/POOL --poolmetadata snapper_thinp/meta_swap.269
[root@megatest-11 ~]# lvremove -f snapper_thinp/meta_swap.269
 Logical volume "meta_swap.269" successfully removed.
[root@megatest-11 ~]# lvchange -ay --yes --select 'lv_name=POOL || pool_lv=POOL'
 Check of pool snapper_thinp/POOL failed (status:64). Manual repair required!
[root@megatest-11 ~]# lvconvert --yes --repair snapper_thinp/POOL /dev/sdb1
no compatible roots found
 Repair of thin metadata volume of thin pool snapper_thinp/POOL failed (status:64). Manual repair required!
[root@megatest-11 ~]# echo $?
5