[CentOS] DISAATER RECOVERY PROBLEM

Tue Mar 27 13:31:47 UTC 2007
Chris Geldenhuis <cgeldenhuis at jhb.ullmanns.co.za>

Matt Hyclak wrote:
> On Fri, Mar 23, 2007 at 01:55:00PM +0200, Chris Geldenhuis enlightened us:
>   
>> I am trying to set up a quick disaster recovery methodology for a 
>> client. It is supposed to work as follows:-
>>
>> All Data files , everything in /etc (except for a few hardware specific 
>> files such as fstab), all users .bashrc and .netrc files, all cron 
>> tables etc. is written to a DVD as a zipped tar file. A recovery script 
>> that unpacks this file, creates any directories required by the 
>> application that are not backed up etc. is also written to the DVD.
>>
>> The DVD is then mounted on a freshly installed system (Centos4.4 at 
>> present) and the restore script is run. This restors all the saved files 
>> on the DVD to their original positions and creates empty directories 
>> where required for the application to run.
>>
>> The recovery system is then rebooted and the differences in hardware are 
>> taken care of by "kudzu" removing hw that was present on the "old" 
>> system and installing hardware present on the "new" system - typically 
>> network cards, usb controllers, scsi controllers, IDE controllers and 
>> graphics cards.
>>
>> All of the above works perfectly.
>>
>> However when I then log in to the recovered system as a user via ssh, or 
>> directly on a tty (non-gui), the login process does not execute the 
>> instructions in the user's .bashrc file and I get a shell prompt with 
>> none of the required environmental variables set - also the last line in 
>> the .bashrc is an exec of a script that bring up the application - this 
>> does not happen.
>>
>> When I log in to the gui desktop as the user and then open a terminal 
>> screen the instructions in the .bashrc do get executed
>> and the application runs as it should.
>>
>> Any ideas of where to look ?
>>
>>     
>
> The bash man page, especially the section titled INVOCATION
>
> Matt
>
>   
Hi,

Thanks to all the guys that replied. Experimenting with the flags given 
in the "INVOCATION" section of the bash man page has led me to a 
work-around. I still don't understand why the original set up did not 
work and why this does but I have to move on to the next project.

The work around is to edit the /etc/passwd file with sed in the recovery 
script and change all the /bin/bash fields at the end of the user's 
lines to /bin/bash -i. The exception is root - if root is changed the 
"su" command does not work.

It works equally well if just a space is appended to the users lines in 
/etc/passwd.

Logging in as a user on the gui screen and then starting a Terminal 
screen no longer works. This is a minor inconvenience  as users are not 
supposed to work on the systems console.

Thanks again

ChrisG