IBM s/390 manual Using tar and ftp

5.We intended to use the cmp command to verify that the restored file matched the original file, but it appears that this command does not work with files larger than 2 GB.

The complete operation took place on a single HDD in the ThinkPad. Linux disk buffering was very effective and HDD seeking was not excessive during these operations, judging both from the sound of the HDD and observed performance.

The disadvantage of this backup method is that single S/390 data sets cannot be restored from the backup file. (Of course, you could restore the file containing the S/390 volume, rename the file, add it to your FLEX-ES definitions, IPL, clip the S/390 volume to a different volser, vary it online, and copy a single file from it. This is an extended process, but it does work for simple data sets. Attempting to deal with VSAM data sets, for example, could be more complex.)

We did not try this, but we could have first backed up the S/390 volume (with ADRDSSU) to create a FakeTape file and then processed this file with tar. This would require more processing and more Linux disk space, but this process could be used to restore individual OS/390 data sets.

5.15.2 Using tar and ftp

One way to back up S/390 volumes on a ThinkPad/EFS system is to ftp the Linux file containing the volume to another system. Using a 100 Mpbs LAN connection, especially on a private or local LAN, performance can be quite good. These files are large, by any standard, and ftp’ing compressed files probably makes more sense. We created the following shell scripts:

Shell script /usr/flexes/rundir/buOS39RAc

tar -cvzf /holding/OS39RA.tarz /s390/OS39RA ftp -niv 0<buOS39RAp

Shell script /usr/flexes/rundir/buOS39RAp

open 9.12.17.220 user ogden xxxxxx bin

put /holding/OS39RA.tarz /s390/TP/OS39RA.tarz

We then executed these functions:

$cd /usr/flexes/rundir

$sh buOS39RAc

tar: Removing ‘/’ from member names s390/OS39RA

Connected to 9.12.17.220

220 nfefs1 FTP server (Version wu-2.6.1-16) ready 530 Please login with USER and PASS.

530 Please login with USER and PASS.

KERBEROS_V4 rejected as an authentication type 331 Password required for ogden.

230 User ogden logged in/

200 Type set to I.

local: /holding/OS39RA.tarz remote: /s390/TP/OS39RA.tarz 226 Transfer complete

468091178 bytes sent in 57 seconds (8e+03 Kbytes/s)

221-You have transferred 468091178 bytes in 1 files.

221-Total traffic for this session was 468091705 bytes in 1 transfers. 221 Thank you for using the FTP server on nfefs1

Chapter 5. Additional Topics 55