The file system /dev/sda1, which is mounted at /boot, has reached warn status because it is 90.33% full.

Once a day I got the below warning.
When I talk with my hosting company they say that "There is nothing to worry. The boot directory has only the OS and it is not possible to write a file there."

Do they right? There is nothing to worry?

The file system /dev/sda1, which is mounted at /boot, has reached warn status because it is 90.33% full.

Server:      xxxx.com
Primary IP:      89.19.23.154
Notification Type:      warn
Filesystem:      /dev/sda1
Mount Point:      /boot
Percentage Full:       90.33%
Disk Information:      
Used: 89.22 MB
Available: 9.54 MB
Total: 98.76 MB
ChkServd Version:      15.8