Differences between JFS and Enhanced JFS

There are many differences between JFS and Enhanced JFS.

Table 1. Functional Differences between JFS and Enhanced JFS
Function JFS Enhanced JFS
Optimization 32-bit kernel 64-bit kernel
Maximum file system size 32 TB 32 TB
Maximum file size 64 GB 16 TB
Number of I-nodes Fixed at file system creation Dynamic, limited by disk space
Large file support As mount option Default
Online defragmentation Yes Yes
namefs Yes Yes
Compression Yes No
Quotas Yes Yes
Deferred update Yes No
Direct I/O support Yes Yes
  • Cloning with a system backup with mksysb from a 64-bit enabled JFS2 system to a 32-bit system will not be successful.
  • Unlike the JFS file system, the JFS2 file system will not allow the link() API to be used on its binary type directory. This limitation may cause some applications that operate correctly on a JFS file system to fail on a JFS2 file system.