Note, that the logs you pasted were not in the logs attached; they appear to be different issues. Namely, the description:
Stdout: Invalid number 0 of holding devices: "[]" An error occured handling 'bcache0': ValueError - Invalid number 0 of holding devices: "[]"
Indicates a make-bcache failure; the kernel did not bind a backing device to a bcacheN device. This is also likely related to bcache over RAID5.
Note, that the logs you pasted were not in the logs attached; they appear to be different issues. Namely, the description:
Stdout: Invalid number 0 of holding devices: "[]"
An error occured handling 'bcache0': ValueError - Invalid number 0 of holding devices: "[]"
Indicates a make-bcache failure; the kernel did not bind a backing device to a bcacheN device. This is also likely related to bcache over RAID5.