I managed to copy parts of the sys log.
Moved the VM from Cache to HDD and so far no issues. Didn't test with a new VM on the SSD cache yet as I am afraid this will trouble the parity disk again.
Any further advise?
Nov 20 08:30:31 Ryzen kernel: BTRFS error (device loop2): bdev /dev/loop2 errs: wr 2, rd 0, flush 0, corrupt 0, gen 0
Nov 20 08:30:34 Ryzen kernel: blk_update_request: I/O error, dev loop2, sector 149152 op 0x1:(WRITE) flags 0x1800 phys_seg 3 prio class 0
Nov 20 08:30:34 Ryzen kernel: BTRFS error (device loop2): bdev /dev/loop2 errs: wr 3, rd 0, flush 0, corrupt 0, gen 0
Nov 20 08:30:34 Ryzen kernel: blk_update_request: I/O error, dev loop2, sector 153248 op 0x1:(WRITE) flags 0x1800 phys_seg 35 prio class 0
Nov 20 08:30:34 Ryzen kernel: BTRFS error (device loop2): bdev /dev/loop2 errs: wr 4, rd 0, flush 0, corrupt 0, gen 0
Nov 20 08:30:34 Ryzen kernel: BTRFS error (device loop2): bdev /dev/loop2 errs: wr 5, rd 0, flush 0, corrupt 0, gen 0
Nov 20 08:30:34 Ryzen kernel: BTRFS error (device loop2): bdev /dev/loop2 errs: wr 6, rd 0, flush 0, corrupt 0, gen 0
Nov 20 08:30:34 Ryzen kernel: blk_update_request: I/O error, dev loop2, sector 673440 op 0x1:(WRITE) flags 0x1800 phys_seg 3 prio class 0
Nov 20 08:30:34 Ryzen kernel: BTRFS error (device loop2): bdev /dev/loop2 errs: wr 7, rd 0, flush 0, corrupt 0, gen 0
Nov 20 08:30:34 Ryzen kernel: blk_update_request: I/O error, dev loop2, sector 677536 op 0x1:(WRITE) flags 0x1800 phys_seg 35 prio class 0
Nov 20 08:30:34 Ryzen kernel: BTRFS error (device loop2): bdev /dev/loop2 errs: wr 8, rd 0, flush 0, corrupt 0, gen 0
Nov 20 08:30:34 Ryzen kernel: BTRFS error (device loop2): bdev /dev/loop2 errs: wr 9, rd 0, flush 0, corrupt 0, gen 0
Nov 20 08:30:34 Ryzen kernel: BTRFS error (device loop2): bdev /dev/loop2 errs: wr 10, rd 0, flush 0, corrupt 0, gen 0
Nov 20 08:30:34 Ryzen kernel: blk_update_request: I/O error, dev loop2, sector 156928 op 0x1:(WRITE) flags 0x1800 phys_seg 1 prio class 0
Nov 20 08:30:34 Ryzen kernel: blk_update_request: I/O error, dev loop2, sector 681216 op 0x1:(WRITE) flags 0x1800 phys_seg 1 prio class 0
Nov 20 08:30:34 Ryzen kernel: BTRFS: error (device loop2) in btrfs_commit_transaction:2327: errno=-5 IO failure (Error while writing out transaction)
Nov 20 08:30:34 Ryzen kernel: BTRFS info (device loop2): forced readonly
Nov 20 08:30:34 Ryzen kernel: BTRFS warning (device loop2): Skipping commit of aborted transaction.
Nov 20 08:30:34 Ryzen kernel: BTRFS: error (device loop2) in cleanup_transaction:1898: errno=-5 IO failure
Nov 20 08:30:40 Ryzen smbd[24055]: [2020/11/20 08:30:40.654245, 0] ../../source3/smbd/service.c:850(make_connection_snum)
Nov 20 08:30:40 Ryzen smbd[24055]: make_connection_snum: '/mnt/user/isos' does not exist or permission denied when connecting to [isos] Error was Input/output error
Nov 20 08:30:40 Ryzen smbd[24055]: [2020/11/20 08:30:40.655062, 0] ../../source3/smbd/service.c:850(make_connection_snum)
Nov 20 08:30:40 Ryzen smbd[24055]: make_connection_snum: '/mnt/user/isos' does not exist or permission denied when connecting to [isos] Error was Input/output error
Nov 20 08:30:40 Ryzen smbd[24055]: [2020/11/20 08:30:40.655821, 0] ../../source3/smbd/service.c:850(make_connection_snum)
Nov 20 08:30:40 Ryzen smbd[24055]: make_connection_snum: '/mnt/user/isos' does not exist or permission denied when connecting to [isos] Error was Input/output error