问题
Is there a way to determine the journal file size based on a data file size?
For example, I've arrived at a data file size of 10 GB (approximately) based on data + index length considerations and preallocation.
I understand journal is also pre-allocated (after every 1GB file size). So, for 10 GB data file, is it possible to assume journal will also be 10 GB? Or is there any other way to calculate it?
回答1:
The MongoDB journal files are fixed size 1GB files (unless you use the smallfiles option). There will be at most three 1GB journal files, so you will never have more than 3GB of journal.
http://docs.mongodb.org/manual/core/journaling/
来源：https://stackoverflow.com/questions/26549992/mongodb-journal-file-size-relation-to-data-file-size