Strange failure during DB2 Installation

Body

db2_install / installfixpack fails with "DBI1058E gunzip command not found" error.

# ./db2_install -b /opt/tivoli/tsm/db2                                 
DBI1324W  Support of the db2_install command is deprecated.            
DBI1058E  gunzip command not found.                                    
                                                                       
Explanation:                                                           
The gunzip utility must be available on your system to install or update DB2 products.                                                          
User response:                                                         
Ensure the gunzip utility is installed in the PATH environment variable.

PATH variable if correctly set:

PATH=/usr/bin:/etc:/usr/sbin:/usr/ucb:/usr/bin/X11:/sbin:/usr/java5/jre/bin:/usr/java5/bin:/usr/opt/ifor/ls/os/aix/bin:/usr/bin:/usr/websm/bin:/usr/local/nmon:/admin/ATAPE/atape12280:/usr/local/bin

>id
uid=0(root) gid=0(system) groups=2(bin),3(sys),7(security),8(cron),10(audit),11(lp)

> gunzip -V 
gunzip 1.2.4 (18 Aug 93)
Compilation options:
DIRENT UTIME STDC_HEADERS HAVE_UNISTD_H

> which gunzip
/usr/bin/gunzip 
 

> ls -ltra /usr/bin/gunzip
lrwxrwxrwx    1 root     system           28 Sep 22 2011 /usr/bin/gunzip -> /usr/opt/freeware/bin/gunzip

 So this looks good!
  

Here is the script trace using export setopts=-x of db2_install

export setopts=-x
>./db2_install -b /opt/tivoli/tsm/db2
...
...
<snip>
...
...

+ /usr/bin/dspmsg /tsmarchfail01/upgrade/7.1.5.1srv/repository/native/pmr/ese/db2/aix/install/locale/en_US.iso88591/db2install.cat 5019 yes
YES=yes
+ display_msg /tsmarchfail01/upgrade/7.1.5.1srv/repository/native/pmr/ese/db2/aix/install/locale/en_US.iso88591/db2install.cat 5020 no
+ set -x
+ unset catname msgid deftmsg msgstr
catname=/tsmarchfail01/upgrade/7.1.5.1srv/repository/native/pmr/ese/db2/aix/install/locale/en_US.iso88591/db2install.cat
msgid=5020
deftmsg=no
+ shift
+ shift
+ shift
+ /usr/bin/dspmsg /tsmarchfail01/upgrade/7.1.5.1srv/repository/native/pmr/ese/db2/aix/install/locale/en_US.iso88591/db2install.cat 5020 no
+ /usr/bin/sed -e s/\r//
NO=no
+ display_warning
+ set -x
+ display_msg /tsmarchfail01/upgrade/7.1.5.1srv/repository/native/pmr/ese/db2/aix/install/locale/en_US.iso88591/db2install.cat 324 DBI1324W Support of the %s command is deprecated. For more

information, see the DB2 Information Center.\n db2_install
+ set -x
+ unset catname msgid deftmsg msgstr
catname=/tsmarchfail01/upgrade/7.1.5.1srv/repository/native/pmr/ese/db2/aix/install/locale/en_US.iso88591/db2install.cat
msgid=324
deftmsg=DBI1324W Support of the %s command is deprecated. For more information, see the DB2 Information Center.\n
+ shift
+ shift
+ shift
+ /usr/bin/dspmsg /tsmarchfail01/upgrade/7.1.5.1srv/repository/native/pmr/ese/db2/aix/install/locale/en_US.iso88591/db2install.cat 324 DBI1324W Support of the %s command is deprecated. For

more information, see the DB2 Information Center.\n db2_install
DBI1324W  Support of the db2_install command is deprecated.

ESE_triggers=db2ese.lic db2ese_o.lic db2ese_c.lic db2ese_u.lic db2ese_t.lic db2wse_o.lic
CONSV_triggers=db2consv.lic db2consv_o.lic db2consv_c.lic db2consv_u.lic db2consv_t.lic
CLIENT_triggers=client
RTCL_triggers=rtcl
+ check_gunzip
+ set -x
+ sh_which gunzip
+ set -x
+ sh_which_ gunzip
+ set -x
file=gunzip
search_path=
+ [ -z  ]
search_path=.:/usr/bin:/etc:/usr/sbin:/usr/ucb:/usr/bin/X11:/sbin:/usr/java5/jre/bin:/usr/java5/bin:/usr/opt/ifor/ls/os/aix/bin:/usr/bin:/usr/websm/bin:/usr/local/nmon:/admin/ATAPE/atape122
80:/usr/local/bin
+ /usr/bin/echo
.:/usr/bin:/etc:/usr/sbin:/usr/ucb:/usr/bin/X11:/sbin:/usr/java5/jre/bin:/usr/java5/bin:/usr/opt/ifor/ls/os/aix/bin:/usr/bin:/usr/websm/bin:/usr/local/nmon:/admin/ATAPE/atape12280:/usr/local/bin
+ /usr/bin/sed -e s/:/\
/g
+ read path
text=
+ [ -z  ]
+ return 1
+ [ 1 -ne 0 ]
+ display_msg /tsmarchfail01/upgrade/7.1.5.1srv/repository/native/pmr/ese/db2/aix/install/locale/en_US.iso88591/db2install.cat 58 DBI1058E gunzip command not found.
+ set -x
+ unset catname msgid deftmsg msgstr
catname=/tsmarchfail01/upgrade/7.1.5.1srv/repository/native/pmr/ese/db2/aix/install/locale/en_US.iso88591/db2install.cat
msgid=58
deftmsg=DBI1058E gunzip command not found.
+ shift
+ shift
+ shift
+ /usr/bin/dspmsg /tsmarchfail01/upgrade/7.1.5.1srv/repository/native/pmr/ese/db2/aix/install/locale/en_US.iso88591/db2install.cat 58 DBI1058E gunzip command not found.
DBI1058E  gunzip command not found.

Explanation:
The gunzip utility must be available on your system to install or update DB2 products.
User response:
Ensure the gunzip utility is installed in the PATH environment variable.Reenter the command.

+ exit 67

Then, the truss command shown this :

3605258: 7602997: execve("/usr/bin/echo", 0x201264E0, 0x201264EC) Err#8 ENOEXEC

Looking at OS doc it means :

       ENOEXEC
              An executable is not in a recognized format, is for the wrong architecture, or has some other format error that means it cannot be executed.

So focussed attention towards echo file.

>which echo
/usr/bin/echo
 

> ls -eal /usr/bin/echo
-r-xr-xr-x-    1 bin      bin               0 May 25 2016  /usr/bin/echo

0 byte file!
 

After getting assistance from sys admin ( where the DB2 DBA replaced the echo file from other good system) the db2 installation worked fine.
Apparently the *good* copy of echo was overwritten by some other script/program by mistake from client side.