Sometimes, you can get the following error on VPS while running easy apache. You can fix by simple following steps.
Login in to main VPS and edit the variable PRIVVMPAGES accordingly
Use of uninitialized value in pattern match (m//) at /var/cpanel/perl/easy/Cpanel/Easy/Utils.pm line 436.
!! Critical Error (VZ): You are only only allowed to use 90 Megabytes of ram! 512 Megabytes is required. !!
You can also modify the privvmpages values from shell as required. (For OpenVZ users) :
vzctl set 101 --privvmpages 850M:900M --save