Hi Varun,
Here are my answers :
1) While updating caf.enu file across all the 20K agents, Assume due to some issue caf.enu is not updated. will there be any problem on agent machines ?.
No machines with original version of caf.enu file will work without problem. It will display the default message defined in caf.enu
2) Also, In support documents could see that before any version upgrade back up the customization and proceed with version upgrade. what all folders we need to take back up ?
In case of updated file caf.enu I think nothing should be backuped on the agent. Upgrade may update the file caf.enu with new or updated messages.
So in case of upgrade, you should update again the file caf.enu using the latest version of caf.enu and deploy it again on all machines after the upgrade.
3) what if caf.enu is corrupted due to some reasons while distributing the SD package. Does that break the functionality of ITCA agent on target machine ?
If caf.enu is corrupted on a machine, ITCM Agent may not work anymore (it depends of the corruption).
The solution is to restore the caf.enu file using another method than using ITCM Agent as it is not working anymore.
4) Changing the text and reboot dialog is it best practice and supported by CA ?
Yes it is supported by CA as the method is documented in CA Document online.
Thanks.
Regards,
Jean-Yves