12.1 HFS and zFS file system comparison We created a simple test scenario to compare large file access behavior between HFS and zFS. Following are the steps that were performed to prepare and perform the tests. 12.1.1 zFS cache sizes zFS was started with the cache sizes shown in Figure 12-1. The results are shown as ZFS1 in Table 12-1 on page 464. ********************************************************************** * zSeries File System (zFS) Sample Parameter File: ioefsprm ... *adm_threads=5 *auto_attach=ON user_cache_size=256M log_cache_size=64M sync_interval=60 *vnode_cache_size=5000 nbs=off *fsfull(85,5) *aggrfull(90,5) ... Figure 12-1 zFS cache sizes defined in IOEFSPRM HFS cache size We started with the HFS cache size value shown in Figure 12-2.