SAP Note 13116 - Changing File_System_Fragment_Size later

Symptom:

The system gives out a warning with different values of the operating system parameters:
filesystem_fragment_size
filesystem_block_size
oracle_block_size

Cause and prerequisites

"sloppy" system installation or other (possibly compelling) operating system-based causes

Solution
Earlier systems sometimes had problems with different block or fragment sizes. These problems have all been solved by now.
Also, performance problems hardly still occur. Thus, it is in general not necessary to make the rather time-consuming changes of these parameters unless unusual reasons exist.

For this change you would need:
usually all ../sapdata mit UNIX means (tar, cpio ...)
- Reformatting the affected disks/disk areas using Unix tools
(e.g. newfs).
- Reloading the offline backup.

In the case of reinstallations, the three parameters should agree as much as possible. If there is disagreement, SAPDBA issues a warning only on the first check; generally, this can be ignored.

Warning:
Do NOT use the sysback tool for backing up on AIX systems, as sysback does not save any blocks that only contain hex-zero values. Oracle uses hex-zeroes to initialize its blocks, however, and needs these blocks, too!