Found in z/OS 2.4 File System Administration For zFS read/write sysplex-aware file systems, zFS takes responsibility for determining how to access the data. This means that zFS must have the concept of a file system owner to coordinate file requests. That system is the zFS owner. z/OS UNIX has its indication of owner, which is called the z/OS UNIX owner. The zFS owner is independent of the z/OS UNIX owner. The zFS owner is the system that coordinates file access. The z/OS UNIX owner generally does not have any performance implications when zFS runs sysplex-aware because file requests are sent to the local zFS rather than being function shipped to the z/OS UNIX owner. There are some cases when the z/OS UNIX owner is relevant (see “When is the z/OS UNIX owner important?” on page 51).
In Figure 11 on page 50, SY2 is the z/OS UNIX owner and the zFS owner. This is typically the case for the system where the mount was issued. If SY2 goes down, a new zFS owner is chosen randomly (such as SY3) and a new z/OS UNIX owner is chosen randomly (such as SY1) assuming it was mounted with AUTOMOVE. Figure 11 on page 50 shows the situation after SY2 has come back up. (zFS on SY1 communicates directly with zFS on SY3.) The fact that SY1 is the z/OS UNIX owner is not important for performance in this case. For zFS non-sysplex aware file systems, the z/OS UNIX owner and the zFS owner are always the same system. ...sounds like the ownership transfer is random. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
