Migrating an ADCD z/OS release: ZFS files.

Start here:Migrating an ADCD z/OS release to the next release.

For background see Should I use tar or pax to backup my Unix files?

System files

If you have done any configuration to products which use Unix services, you are likely to have changed files in the file system. For example /etc/syslog.conf.

Configuration files

Many configuration files are configured in the /etc directory.

If you want to find which files have been changed since you have been using the system you could use the ls -ltr command to display the files in each directory, displayed with the latest changed date at the bottom.

This gets very tedious when you have a lot of directories to example. However you can ask Unix to list all files which match a critera, such as changed in the last n days, or newer than an existing file.

Create a file of the comparison data

touch -t 202202211456 /tmp/foo

This creates a file /tmp/foo with the given date year 2022 month 02 date 21 time 1456

find . -type f -newer /tmp/foo |xargs ls -ltr > aa

This is two commands.

• The find command
  • looks in the current directory (.) and subdirectories
  • for objects with type of files (rather than directories etc)
  • which have been changed more recently than /tmp/foo.
• The file name is passed to the ls -ltr command to display the date time information.

-rwx------   1 OMVSKERN OMVSGRP       32 Feb 13  2023 ./cssmtp.env 
-rw-r--r--   1 OMVSKERN OMVSGRP     3453 Feb 13  2023 ./mail/ezatmail.cf 
-rwxr-xr-x   1 OMVSKERN OMVSGRP      250 Feb 28  2023 ./hosts 
-rw-r--r--   1 OMVSKERN OMVSGRP   226441 Jun 16  2023 ./pkiserv/pkiserv.tmpl.old 
-rw-r--r--   1 OMVSKERN OMVSGRP    22406 Jun 16  2023 ./pkiserv/pkiserv.conf.old 
...

if you use

find . -type f -newer /tmp/foo |tar -cvf ~/etc.tar –

it will create a tar file containing the changed files. You can then transport the etc.tar file to the newer system and untar it.

You can use the pax command to package the files

find . -type f -newer /tmp/foo |pax -W “seqparms=’space=(cyl,(10,10))'” -o saveext -wzvf “//’COLIN.PAX.TEST'” -x os390

to save the files in pax format into the data set COLIN.PAX.TEST. If the high level qualifier has been defined as an alias is the master catalog on both systems, the data set will be visible on both systems.

Note: If you specify

find . -type d -newer /tmp/foo

It displays all directory entries which have been changed, and displays all the files within those directories.

For example

total 1344 
-rw-r--r--   1 OMVSKERN OMVSGRP     3252 May  7  2019 ssh_config 
-rw-r--r--   1 OMVSKERN OMVSGRP   553761 May  7  2019 moduli 
-rwx------   1 OMVSKERN OMVSGRP       65 Oct 29  2019 sshd.sh 

For example the sshd directory was changed in September this year, so all the files below it are listed. 

Application output files

These are usually in the /var sub-directory. You may not need to move these files across.

User data

You will have your own data in the Unix file systems. If you put the data under the /u file system it should be easy to find! 

You may have configured userids so their home directory is on a “user” ZFS file system, or your home directory could be mixed in with the systems files. For example the file system for IBMUSER is on an ADCD file system (D5USS2).

IBMUSER:/S0W1/etc: >df -P ~                                                         
Filesystem          512-blocks        Used  Available  Capacity Mounted on          
ZFS.USERS              2880000     1277970    1602030       45% /u                   

The newer system also has a ZFS.USERS. You cannot have both old and new ZFS.USERS mounted at the same time, as the mount takes cataloged data set.

For my application data

IBMUSER:/S0W1/etc: >df -P /u/tmp
Filesystem 512-blocks Used Available Capacity Mounted on
COLIN.ZFS2 2817120 788338 2028782 28% /u/tmp

I can take this ZFS system and mount it on the newer system.

You can tar up the files under a directory and move the tar file to the new system, or you can use pax which I think is better, as it creates a dataset out of the ZFS files.

Using tar

Note: if you use an absolute path in the tar command, when you untar the data it will use the same directory- – which may overrwrite data you wanted to keep.

If you use are relative directory, the data is untarred relative to the current directory.

cd /u/colin
tar -cvf ~/relative.tar *

is better than

tar -cvf ~/absolute.tar /u/colin

On the new system if I use

mk dir oldcolin
cd oldcolin
tar -xtvf relative.tar

it will restore the files in oldcolin.

If I use

mk dir oldcolin
cd oldcolin
tar -xtvf absolute.tar *

it will restore the files to /u/colin – and overwrite any files which were there.

What directories were created?

You can use the command

find /u -type d -newer /tmp/foo |xargs ls -ltrd> aa

to display the directories created/modified since the time of the /tmp/foo file.

This gives output like

drwxrwxrwx  10 OMVSKERN SYS1        8192 Dec  8 13:04 ./adcd 
drwxr-xr-x   2 OMVSKERN 1000        8192 Mar 15  2023 ./tmp/oemput 
drwxrwxrwx   2 OMVSKERN WEBGRP      8192 Apr 25  2023 ./mqweb3/logs 
drwxr-xr-x   2 OMVSKERN SYS1        8192 Jun 16  2023 ./mqweb2/oldconf 

You can use the pax -E option to display the contents and extended attributes.

pax -E -f "//'COLIN.PAX.HTTP2'"

Notes the double / and both sets of quotes.

To unpax the files on the new system, cd into the directory and use

pax -k -rvf  "//'COLIN.PAX.TEST'" .

The

• -k means do not overwrite
• -r read
• -v display the details
• -f from the following file
• into . (the current directory)

To mount a ZFS on the system

You can have an entry in an BPXPRMxx parmlib member, so a ZFS is mounted at IPL time.

You can also use a TSO command, or a batch job to mount a ZFS

//IBMMFAMO JOB 1,MSGCLASS=H
//MOUNT EXEC PGM=IKJEFT1A
//SYSTSPRT DD SYSOUT=*
//SYSTSIN DD *
MOUNT FILESYSTEM('AZF220.ZFS') TYPE(ZFS) +
MOUNTPOINT('/u/mfa') +
MODE(RDWR) PARM('AGGRGROW') AUTOMOVE

Sharing File systems

You can display the mounted file systems using the D OMVS,F command

This gives output like

ZFS            16 ACTIVE                      RDWR  01/15/2024  L=30  
  NAME=ZFS.USERS                                    14.38.54    Q=0   
  PATH=/u                                                             
  OWNER=S0W1     AUTOMOVE=N CLIENT=N
ZFS            37 ACTIVE                      RDWR  01/15/2024  L=48   
  NAME=COLIN.ZFS2                                   14.38.56    Q=0    
  PATH=/u/tmp                                                          
  OWNER=S0W1     AUTOMOVE=Y CLIENT=N                                                                     

This shows there are two ZFS file systems, both mounted read/write. The first has

• data set name ZFS.USERS. On the z24C system – this is the z24C file system. You cannot mount both the z24C, and the z25D file systems at the same time, because the mount command uses the cataloged data set.
• mounted as path /u

The second has

• data set name COLIN.ZFS2
• mounted as path /u/tmp

You can choose to mount your data under an existing path, or create a new tree such as “/my”.