Tag: tar

How hard can it be to copy a directory on z/OS

My home directory had filled up, and I wanted to copy my files to a file system with more space. This took me much longer than I expected.

Philippe Richard said you should take a look at copytree (in /samples). Nice tool to clone/copy directories. can be run as a unix script or under TSO REXX.

copy using cp

I used cp -R olddir newdir but not all of the files were copied.

tar complained

I used tar -cf old /u/colin/* but got

FSUM7218 tar: /u/colin/env/lib/python3.12/….pyc: name too long

I got pax wrong (1)

I used

pax -w – -f /u/tmp/zowet/archive /u/colin/*

The gave message

FSUMF319 File tag exists but pax cannot store the tag information using this format/option(s) for file /u/colin/env/lib…json.py

I needed the -x os390 option

I got pax wrong (2)

pax -w -x os390 -f /u/tmp/zowet/archive /u/colin/*

The backup worked fine. Unfortunately when I restored from the archive it overwrote the same directory – because I had explicitly coded the fully qualified name /u/colin.

I got pax wrong (3)

cd /u/colin
pax -w -x os390 -f /u/tmp/zowet/archive .

The files are relative to the directory (.) when the files are restored they are also relative to the directory

cd /u/tmp/zowet/colin
pax -ppx -rvf /u/tmp/zowet/archive

This command unpaxes the files from /u/tmp/zowet/archive into the current directory, and prints out the names (-v) as it does so.

The names were displayed, like

./bsdel.sh

so you can see the file name is a relative, rather than fully qualified.

It looked like it worked – but the files belonged to the userid that created them from the pax file.

I got pax right

pax -ppox -rvf ../archive

The -p option specifies which file characteristics to restore

  • o Preserves the user ID and group ID.
  • p Preserves the file mode: access permissions (without modification by umask), set-user-ID bit, set-group-ID bit, and sticky bit.
  • x Preserves extended attributes

I’m sure there are other methods to do the copy.

Oh p*x, I’ve lost my changes

I have been using pax to backup the files in my Unix Services directory and needed to restore a file so I could compare it with the last version (and work out why my updates didn’t work). Unfortunately I managed to overwrite my latest version instead of creating a copy.
I backed up my directory using

pax -W “seqparms=’space=(cyl,(10,10))'” -wzvf “//’COLIN.PAX.PYMQI2′” -x os390 /u/tmp/pymqi2/

This created a data set COLIN.PAX.PYMQI2 with the give space parameters, and os390 format.
(If you do not want all the files listed, use –wzf)

To list the contents of this file use

pax -f “//’COLIN.PAX.PYMQI2′”

To display a subset of the files use

pax -f “//’COLIN.PAX.PYMQI2′” /u/tmp/pymqi2/code

which gave

/u/tmp/pymqi2/code/
/u/tmp/pymqi2/code/pymqi/
/u/tmp/pymqi2/code/pymqi/__init__.py
/u/tmp/pymqi2/code/pymqi/old__init__.old
/u/tmp/pymqi2/code/pymqi/aa

And provide more information using the -v option

drwxrwxrwx 1 COLIN    1000      0 Jan 22 17:04 /u/tmp/pymqi2/code/
drwxr-xr-x 1 COLIN    1000      0 Feb 11 13:10 /u/tmp/pymqi2/code/pymqi/
-rw-r--r-- 1 OMVSKERN 1000 133011 Feb 22 13:15 /u/tmp/pymqi2/code/pymqi/init.py
-rw-r----- 1 COLIN    1000 119592 Feb  3 12:59 /u/tmp/pymqi2/code/pymqi/old__init__.old
-rwx------ 1 OMVSKERN 1000 119565 Jan 22 16:43 /u/tmp/pymqi2/code/pymqi/aa

The whoops

To restore an individual file and overwrite the original I used the -r option.

pax -rf “//’COLIN.PAX.PYMQI2′” /u/tmp/pymqi2/pymqi/__init__.py

I was expecting the file to be restored relative to the directory I was in; No – because I had backed up the files using an absolute path it restored the file to the same place, and so it overwrote my changes to the file. I had changed to a temporary directory, but I had not realised how the command worked.

There are several ways of doing it properly.

Restore with rename

pax -rf “//’COLIN.PAX.PYMQI2′” -i /u/tmp/pymqi2/pymqi/__init__.py

The -i option means rename.

I ran the command and it prompted me to rename it

Rename “/u/tmp/pymqi2/pymqi/__init__.py” as…

/tmp/oldinit.py

Set “do not overwrite”

I could also have used the -k option which prevents the overwriting of existing files.

Rename on restore

I could also have used the rename

pax -rf “//’COLIN.PAX.PYMQI2′” -s#/u/tmp/pymqi2/pymqi#/tmp/# /u/tmp/pymqi2/pymqi/__init__.py

Where the -s#/u/tmp/pymqi2/pymqi#/tmp/# / says use the regular expression to change /u/tmp/pymqi2/pymqi to /tmp and so restore it to a different place. Note: The more obvious -s/abc/xyz/, where / is used as the delimiter, would not work, as there is a ‘/’ in the file path.

All of the above

I could have use all of the options -i -k -s…. .

A better way to backup.

I had specified an absolute directory /u/tmp/pymi2/. If I was in this directory when I did the backup I could have used

pax … -x os390 .

Where the . at the end means from this directory, and so backup a relative directory.

If I list the files I get

pax -f “//’COLIN.PAX.PYMQI2A'” ./aa
./aa

And now if I restore the file…

pax -rf “//’COLIN.PAX.PYMQI2A'” ./aa

It restored the file into my working directory /tmp/aa .

So out of all the good ways of backing up and restoring – I chose the worst one. It only took me about 2 hours to remake all the changes I had lost.