IBM recommends disabling the chacha20-poly1305@openssh.com cipher (Terrapin) by upgrading to one of the versions in “Remediation/Fixes” above and then running the commands below:

versions not affected (or higher) 8.4.0.14, 8.5.0.12, 8.6.0.4, 8.6.2.1, 8.6.3.0, 8.7.0.0

From the CLI

IBM_FlashSystem:V5100-01:superuser> chsecurity -sshprotocol 4

Using the GUI (8.6.0 and higher)

Settings > Security > Security Protocol Levels and choose SSH protocol level 4 in the GUI.

Which WWN should I use to connect hosts to storage (check the host_io_permitted)

IBM_FlashSystem:V5100-01:superuser>lstargetportfc
id WWPN             WWNN             port_id owning_node_id current_node_id nportid host_io_permitted virtualized protocol
1  50050xxxx0215A04 50050xxxx0005A04 1       1                              000000  no                no          scsi
2  50050xxxx0255A04 50050xxxx0005A04 1       1                              000000  yes               yes         scsi
3  50050xxxx0295A04 50050xxxx0005A04 1       1                              000000  yes               yes         nvme
4  50050xxxx0225A04 50050xxxx0005A04 2       1                              000000  no                no          scsi
5  50050xxxx0265A04 50050xxxx0005A04 2       1                              000000  yes               yes         scsi
6  50050xxxx02A5A04 50050xxxx0005A04 2       1                              000000  yes               yes         nvme

Remove the 2 paths from disk

svctask chenclosureslot -exclude no -port 1 -slot 7 3
svctask chenclosureslot -exclude no -port 2 -slot 7 3

Then, you can mark fixed the errors present for the drives with:

svctask cheventlog -fix 2331
svctask cheventlog -fix 2337

Check now the drive status, it should reappear if not defect

lsdrive

Check also for bad blocks

IBM_Storwize:v5020:superuser>dumpallmdiskbadblocks