Previous topic |
Next topic |
Contents |
Contact z/OS |
Library |
PDF
Copying each file and directory of the aggregate to a larger data set z/OS Distributed File Service zFS Administration SC23-6887-00 |
|
One method to increase the size of a zFS aggregate is to copy each
file and directory of the aggregate to a larger data set. Figure 1 shows an example of this
approach.
Figure 1. Sample job
to copy each file and directory of an aggregate to a larger data set
This approach uses the pax command to copy the individual
files and directories into an already formatted and empty zFS file
system. Both file systems must be mounted. pax uses the z/OS® UNIX file
and directory APIs to read and write each individual file and directory
of the hierarchy of the file system. (It does not copy lower mounted
file systems because of the -X and -M options.) You
can use the ISHELL command or the automount command with the allocany or allocuser keyword
to create the new larger aggregate to copy into with pax, because
they format the aggregate.
If you are running this job on a system running z/OS V1R13 or later, and the file system was
written to using a prior release of z/OS,
zFS might use more DASD space for the same data than it did on the
prior release. The increase in DASD space can occur for small files
(1 KB in size or less) because beginning with z/OS VR13 zFS does not store data in 1-KB fragments;
instead, it stores data in 8-KB blocks. For example, if the file system
contained 1000 files that are 1 KB in size, on z/OS V1R13 zFS could use a maximum of 10 cylinders
more than on previous releases. You can determine how many files are
in the file system that are 1 KB or less using the following z/OS UNIX command:
After you successfully copy the data, when you are comfortable with the new, larger aggregate, you can delete the old aggregate. |
Copyright IBM Corporation 1990, 2014
|