diff --git a/SOURCES/mkdumprd.8 b/SOURCES/mkdumprd.8
index 7faae57..2ac3d5a 100644
--- a/SOURCES/mkdumprd.8
+++ b/SOURCES/mkdumprd.8
@@ -15,7 +15,13 @@ be loaded in the initramfs (based on configuration retrieved from
 \fI/etc/kdump.conf)\fR
 
 \fBmkdumprd\fR add a new \fBdracut\fR module 99kdumpbase and use \fBdracut\fR
-utility to generate the initramfs.
+utility to generate the initramfs. When generating a kdump initramfs, \fBmkdumprd\fR
+will determine how much disk space is available, if the dump target's available
+space is not greater than the total system memory, \fBmkdumprd\fR will print a
+warning to remind that there might not be enough space to save a vmcore. The
+warning covers extreme scenarios such as the slab explodes with non-zero data or
+a full vmcore, etc. Therefore, need to prevent users from having minimum disk
+space for crash dump.
 
 \fBmkdumprd\fR was not intended for casual use outside of the service
 initialization script for the kdump utility, and should not be run manually.  If
diff --git a/SPECS/kexec-tools.spec b/SPECS/kexec-tools.spec
index 15c4893..cf64485 100644
--- a/SPECS/kexec-tools.spec
+++ b/SPECS/kexec-tools.spec
@@ -1,6 +1,6 @@
 Name: kexec-tools
 Version: 2.0.20
-Release: 40%{?dist}
+Release: 41%{?dist}
 License: GPLv2
 Group: Applications/System
 Summary: The kexec/kdump userspace component
@@ -371,6 +371,9 @@ done
 %endif
 
 %changelog
+* Fri Dec 18 2020 Pingfan Liu <piliu@redhat.com> - 2.0.20-41
+- Doc: improve mkdumprd man page
+
 * Tue Dec 15 2020 Pingfan Liu <piliu@redhat.com> - 2.0.20-40
 - Rework on dracut-module-setup.sh: Use systemctl call to replace ln_r