During several months before every update system action I need to clean up `/boot` directory because it is full. 
I had removed old kernels as described here ([How to free up space on RHEL6 /boot safely?](https://serverfault.com/questions/439090/how-to-free-up-space-on-rhel6-boot-safely)). 

But every time after update - `/boot` is full again.  

Today even after removing previous kernel is NOT enough space for `yum update`.

```
root@CentOS-70-64-minimal:/boot ============================================ [18:05:08]
> l
total 429M
dr-xr-xr-x.  5 root root 5.0K Jan 12 18:04 ./
drwxr-xr-x. 19 root root 4.0K Jan 12 03:16 ../
-rw-r--r--.  1 root root 121K Nov  3 20:18 config-3.10.0-229.20.1.el7.x86_64
drwxr-xr-x.  2 root root 1.0K Nov  1 23:50 grub/
drwxr-xr-x.  6 root root 1.0K Jan 12 18:04 grub2/
-rw-------.  1 root root  39M Nov  1 23:52 initramfs-0-rescue-36bcd6a9e7104f21b1fffdc70a2410ad.img
-rw-------.  1 root root  39M Jun 25  2015 initramfs-0-rescue-3f69b67d93ab47efad188530c7620ce7.img
-rw-------.  1 root root  36M Dec  6  2014 initramfs-0-rescue-5ada9d2ff7154b7d992458e573f12812.img
-rw-------.  1 root root  38M Mar 31  2015 initramfs-0-rescue-6cb1c41831054f7d8c5f96f86852974a.img
-rw-------.  1 root root  39M Aug  8 10:18 initramfs-0-rescue-6d4eff407451426bb985a283f8a50b73.img
-rw-r--r--.  1 root root  25M Jul 10  2014 initramfs-0-rescue-74f877a555c841639922c44507d67b89.img
-rw-------.  1 root root  39M May 13  2015 initramfs-0-rescue-9dcee4fd9cc94410990561ec753679d4.img
-rw-------.  1 root root  18M Nov 14 19:42 initramfs-0-rescue-c3547f9231df4524867357ebcfa979e8.img
-rw-------.  1 root root  36M Dec 16  2014 initramfs-0-rescue-cddab3440a1f487dad750c2d85b023a9.img
-rw-------.  1 root root  36M Feb  2  2015 initramfs-0-rescue-dcfb8dbba18442ce83382fe302f8e256.img
-rw-------.  1 root root  38M Nov 14 19:41 initramfs-3.10.0-229.20.1.el7.x86_64.img
-rw-------.  1 root root    0 Nov 15 03:16 initramfs-3.10.0-229.20.1.el7.x86_64kdump.img
-rw-r--r--.  1 root root 576K Mar 31  2015 initrd-plymouth.img
drwx------.  2 root root  12K Dec  6  2014 lost+found/
-rw-r--r--.  1 root root 235K Nov  3 20:21 symvers-3.10.0-229.20.1.el7.x86_64.gz
-rw-------.  1 root root 2.8M Nov  3 20:18 System.map-3.10.0-229.20.1.el7.x86_64
-rwxr-xr-x.  1 root root 4.8M Nov  1 23:52 vmlinuz-0-rescue-36bcd6a9e7104f21b1fffdc70a2410ad*
-rwxr-xr-x.  1 root root 4.8M Jun 25  2015 vmlinuz-0-rescue-3f69b67d93ab47efad188530c7620ce7*
-rwxr-xr-x.  1 root root 4.7M Dec  6  2014 vmlinuz-0-rescue-5ada9d2ff7154b7d992458e573f12812*
-rwxr-xr-x.  1 root root 4.8M Mar 31  2015 vmlinuz-0-rescue-6cb1c41831054f7d8c5f96f86852974a*
-rwxr-xr-x.  1 root root 4.8M Aug  8 10:18 vmlinuz-0-rescue-6d4eff407451426bb985a283f8a50b73*
-rwxr-xr-x.  1 root root 4.7M Jul 10  2014 vmlinuz-0-rescue-74f877a555c841639922c44507d67b89*
-rwxr-xr-x.  1 root root 4.8M May 13  2015 vmlinuz-0-rescue-9dcee4fd9cc94410990561ec753679d4*
-rwxr-xr-x.  1 root root    0 Nov 14 19:42 vmlinuz-0-rescue-c3547f9231df4524867357ebcfa979e8*
-rwxr-xr-x.  1 root root 4.7M Dec 16  2014 vmlinuz-0-rescue-cddab3440a1f487dad750c2d85b023a9*
-rwxr-xr-x.  1 root root 4.7M Feb  2  2015 vmlinuz-0-rescue-dcfb8dbba18442ce83382fe302f8e256*
-rwxr-xr-x.  1 root root 4.8M Nov  3 20:18 vmlinuz-3.10.0-229.20.1.el7.x86_64*
-rw-r--r--.  1 root root  171 Nov  3 20:18 .vmlinuz-3.10.0-229.20.1.el7.x86_64.hmac

root@CentOS-70-64-minimal:/boot ============================================ [18:05:11]
> df
Filesystem      Size  Used Avail Use% Mounted on
/dev/md2       1008G   96G  862G  10% /
devtmpfs        7.6G     0  7.6G   0% /dev
tmpfs           7.7G     0  7.7G   0% /dev/shm
tmpfs           7.7G   17M  7.6G   1% /run
tmpfs           7.7G     0  7.7G   0% /sys/fs/cgroup
/dev/md1        488M  439M   25M  95% /boot
/dev/md3        1.7T  1.7T     0 100% /home

```