====== LiteSpeed Admin returns 503 error on CloudLinux Server ======
LiteSpeed Admin URL returns 503 error and error log shows "cannot allocate memory". It is due to CloudLinux unlimited setting change.  LiteSpeed Admin runs admin_php as "lsadm" user, normally set as "pmem=0K" in LVE, which means unlimited.  However CloudLinux enforced "0K" as real "0" instead of "unlimited", hence execve() function will fail with "cannot allocate memory".
  
Quick fix for this is:
  lvectl set-user lsadm --pmem=2G