Prior to RHEL 7, runlevels were used to identify a set of services that would start or stop when that runlevel was requested. Instead of runlevels, systemd uses the concept of targets to group together sets of services that are started or stopped.
A target can also include other targets (for example, the multi-user target includes an nfs target). The post below describes steps to boot an RHEL 7 system into emergency or multi-user mode directly from the GRUB.
1. When the server is booting and reaches the grub menu example below.
2. Choose which kernel that needs to be edited, by using the arrow key to highlight the kernel version, then press the letter e key to edit the boot entry. The next screen should look similar to the below example of me selecting the 3.10.0-327.el7.x86_64 kernel for editing.
3. Once on this screen use the arrow keys to arrow down to the line starting with linux, for most systems it will be linux16, but it can also be just linux and linuxefi. Once the blinking cursor is on the linux16 line, press the End key, this will move the cursor to the end of the linux16 line. Then to boot into whichever target is desired, the below can be appended.
For emergency mode
For booting into the emergency target append the below line to the linux16 line.
Fro multi-user mode
For booting into the multi-user target append the below line to the linux16 line.
4. Once the parameter has been appended, press the Ctrl + x key at the same time to boot with the specified parameter.