I tried to config grub2 files following this solution, but it seems not work.
My /etc/default/grub file is :
So, how can I increase the font size?
Personally I would not touch your GRUB configuration files. Instead, I would add a
setfont line to your shell initialization file.
For example, if you are using Bash, you could ask the following line to
if [ $TERM = linux ] then setfont sun12x22 fi
There are lots of different fonts available;
sun12x22 is just one example. See the
setfont man page for more information.
The way to do this on a systemd operating system such as CentOS 7 is to edit the font settings in the
/etc/vconsole.conf file. These settings are applied by the
systemd-vconsole-setup service, which is essentially a glorified way of running
loadkeys before the login services are brought up.
So you would have
FONT=sun12x22 in that file, for example.
Note that the service program allows kernel command-line options such as
vconsole.font to override
/etc/vconsole.conf contents. If you are mucking around with GRUB kernel command-line options, bear this in mind.
vconsole.conf. systemd manual pages. FreeDesktop.org.
systemd-vconsole-setup. systemd manual pages. FreeDesktop.org.