The data pool used to create the file system is the “default” data pool and the location for storing all inode backtrace information, used for hard link management and disaster recovery. For this reason, all inodes created in CephFS have at least one object in the default data pool. If erasure-coded pools are planned for the file system, it is usually better to use a replicated pool for the default data pool to improve small-object write and read performance for updating backtraces. Separately, another erasure-coded data pool can be added (see also Erasure code) that can be used on an entire hierarchy of directories and files (see also File layouts).