NetBackup installation on Linux servers may fail due to changes in POSIX standard version used in the coreutils tools package
The version of tail is the same as coreutils package.
To see the version, issue the following command:
# rpm -qa |grep ^coreutils

If the version of tail is 5.9x, NetBackup installation will fail with the following error message:
error: "tail: cannot open '+2' for reading"

This is due to a change in the way tail works.  Older versions (for example, 5.2.1) work correctly

Some shell tools included in package coreutils such as tail, chown, head, sort, et cetera changed from the POSIX 1992 standard to the POSIX 2001 standard (Single UNIX Specification, version 3 == IEEE Std 1003.1-2001 == ISO/IEC 9945:2002) in the default configuration.

This has also been seen to affect some of the shell scripts included in NetBackup such as available_media, cleanstats, and check_coverage.

The old behavior can be reproduced with this environment variable:
_POSIX2_VERSION=199209

Comparison of old an new style of commands:
 

POSIX 1992	POSIX 2001
tail +3	tail -n +3
head -1	head -n 1
sort +3	sort -k +3
nice -10	nice -n 10
split -10	split -l 10

To get installation to progress, issue:
# export _POSIX2_VERSION=199209
to set this variable globally.  Then, run the installation script

or the install script may be invoked this way:
# _POSIX2_VERSION=199209 /path_to_NBU_install/install