Default size of tmpfs is 128MB and this limit is quickly reached now with various processes putting their log information in there (notably Docker).
Proposal is to make this at least 256MB or bigger to ensure all log files as created under unRAID v6 will fit.
# resize log partition
mount -o remount,size=384m /var/log
I personally had to use at least 384 Megs since each day generated at least a 9.2 Meg file when Dynamix System Activity plugin was installed.