Backup in a file system


I am new to the foundationdb (currently using V6.2.19) backups, and while creating backups in a file system, I observed we have three folders created, kvranges, snapshots, and logs. my cluster has a K-V size of 3.7G and while running the fdbbackup, I observed that the total file size of the snapshots folder was 3.7G. and if writes were happening continuously onto the cluster, the snapshot file size increased as well.

Is this the expected behaviour?

I was under the impression “full backup consists of an inconsistent copy of the data with a log of database changes that took place during the creation of that inconsistent copy”, which means the mutations would be written within the logs folder.

Could someone clarify how the data is stored while backing up? the explanation for RangeFileWriter( in is a bit confusing.

Thanks in advance!