Okay... this is the same error that we encountered before... onto research!
Let's export the database from RHEL 6 again:
I ignored that warning before... but let's see if addressing the max_input_vars config solves the import issue on RHEL7?
Let's find where the php.ini file is located:
php -i | grep "Loaded Configuration File"
we will make a backup of the current one... call it php.ini.pre-rush-changes
now we can edit the php.ini without any worries 
— well.... but with caution:
Giving Apache the boot---
Let's do the same on RHEL7:
php -i | grep "Loaded Configuration File"
vim php.ini
It's commented; let's uncomment it and then give apache a boot.
Nope... still same error; I will revert the change in the php.ini file... as that had no impact it seems!
Try #5: This time, with Views caching disabled, because upon inspecting the import, it turns out that it has error'd out on the caching table each time:
So on the live site, we will not only disable Views caching, but also clear out the cache overall and then export the DB:
As can be seen, Views caching is not disabled... so let's disable it...
Alright, let's re-export and then import again, and see how it fares this time...
Prior to importing, need to drop the half-imported DB:
Alright... we get confirmation that prep DB been dropped... let's import the database again...
Let's check where it stopped...
Yep... it's the same table that is causing the import problem... each failed import has stopped at cache_menu — more research time!
I noticed that there is an option to flush all caches...
so let's try that:
And we export from RHEL6.... and then try importing it to RHEL7........ ......... again
So the file sizes between the previous try and the current one are definitely different... let's see what happens on import:
SAME ERROR... checking the progress (i.e. how much was it able to import...)—
Again, it stopped at cache_menu... so apparently, Flush all caches didn't do what I thought it would do...
There is a sub-sub-menu item "Menu"----let's see if clearing that has any effect?
Prior to clicking that option, here's the cache_menu table on RHEL6—
Clearing menu cache:
cache_menu table on RHEL6 now....
No change :-/
More research....