Different file sizes ?

Hi GATK team,

I have two questions about file size change. I just want to make sure there is no wrong in my pipeline.
Our cluster sometimes kills several jobs without error message.

1. I have recalibrated lots of bam files and their sizes have been enlarged a lot. e.g. the size of a file increased from 3.6G to 6.3G.
2. then I have done the variants calling. the result gvcf files have very different size, but all of them have variants on 22 CHROMs.