Total cache size
In releases prior to z/OS V2R2, the total
storage size available for all the caches in the zFS address space
had to be less than 2 GB. If the cache sizes specified in the IOEFSPRM
file were too large, zFS would terminate. In addition to the zFS
address space caches, storage is necessary for processing file requests
and for the products zFS might use. As a result, the total address
space cache storage was restricted to approximately 1.5 GB.
Use modify
zfs,query,storage to determine the total allocated zFS storage.
See STOR for more information about
determining how much of the available zFS address space storage is
being used by the zFS caches.
In z/OS V2R2, zFS uses 64-bit storage above the
2 GB line. Therefore, zFS cache sizes are no longer restricted by
the 2 GB storage size. Caches start at the minimum size during zFS
initialization, and are allowed to grow as needed to the size specified
in the IOEFSPRM file. Carefully consider how large you want your
zFS caches to be, taking into account such things as the amount of
real and auxiliary storage in your system.
You might see messages IOEZ00188A, IOEZ00662I, or IOEZ00663I, which
indicate that the zFS address space is low on storage. If it continues
to be a problem, consider using zfsadm config to
dynamically decrease the size of caches that
do not reside in data spaces, such as the metadata or vnode caches.
The data in the user file cache is stored in data
spaces, not zFS address space storage.