I had the situation where I am using ZD&T – which is a z/OS emulator running on Linux, where there 3390 disks are emulated on Linux files. I have an old image, and a new image, and I want to use a ZFS from the new image on the old image to test out a fix.
The high level answer to the original question is “it depends”.
Run in a sysplex
This is how you run in a production environment. You have a SYSPLEX, and have a (master) catalog shared by all systems. I cannot create the environment in zD&T. Setting up a sysplex is a lot of work for a simple requirement.
Copy the Linux file
Because the 3390 volumes are emulated as Linux files, you can copy the Linux file and use that file in the old zPTD image, and avoid the risk of damaging the new copy. The Linux file name is different, but the VOLID is the same. I was told you can use import catalog to get this to work. I haven’t tried it.
The cluster is in a shared user catalog.
If the VSAM cluster is defined in a user catalog, and the user catalog can be used on both systems, then the cluster can be used on both systems (but not at the same time). When the cluster is used, information about the active system is stored in the cluster. When the file system is unmounted, or OMVS is shutdown, this system information is removed. If you do not unmount, or shutdown OMVS cleanly, then when the file system is mounted on the other system, the mount will detect the file system was last used on another system, and wait for a minute or so to make sure the other system is inactive. If the mount command is issued during OMVS startup OMVS will wait for this time. If you have 10 file systems shared, OMVS will wait for each in turn – which can significantly delay OMVS start up.
When the cluster is in the master catalog
Someone suggested
You could mount the volume to your new system and import connect the master catalog of the old system to the new one and define the old alias for the ZFS in the new master pointing to the old master which is now a user catalog to the new system. If it’s not currently different, you could rename it on the old system to a new HLQ that is different from the existing one and then do the import connect of the master as a usercat and define the new alias pointing to the old ZFS.
This feels too dangerous to me!
Pax the files in the directory
You can use Pax to unload the contents of the directory to a dataset, then load the data from the dataset on the other system.
cd /usr/lpp....
pax -W “seqparms=’space=(cyl,(10,10))'” -wzvf “//’COLIN.PAX.PYMQI2′” -x os390 .
On the other system
mkdir mydir
cd mydir
pax -rf “//’COLIN.PAX.PYMQI2A'” .
Note when using cut and paste make sure you have all of the single quotes and double quotes. I found they sometimes got lost in the pasting.
ColinPaice 