ルートディレクトリのディスク容量を増やすには？

そのため、サーバーを確認してみるdf -hと、centos-root容量が99％でした。

わずか数日前だけでも根数は87％に過ぎなかった。何らかの理由でそれが速すぎる。スペースを少なくする方法について提案がありますか？

[root@host ~]# df -h
Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/centos-root   50G   50G  713M  99% /
devtmpfs                 3.8G     0  3.8G   0% /dev
tmpfs                    3.8G     0  3.8G   0% /dev/shm
tmpfs                    3.8G  401M  3.4G  11% /run
tmpfs                    3.8G     0  3.8G   0% /sys/fs/cgroup
/dev/mapper/centos-home  873G  136G  738G  16% /home
/dev/sda1                494M  172M  323M  35% /boot

[root@host ~]# du -csh /*
0       /bin
146M    /boot
0       /dev
23M     /etc
136G    /home
0       /lib
0       /lib64
0       /media
0       /mnt
24K     /nginxweblog
990M    /opt
du: cannot access `/proc/61778/task/61778/fd/4': No such file or directory
du: cannot access `/proc/61778/task/61778/fdinfo/4': No such file of directory
du: cannot access `/proc/61778/fd/4': No such file of directory
du: cannot access `/proc/61778/fdinfo/4': No such file of directory
0       /proc
41M     /root
401M    /run
0       /sbin
0       /srv
0       /sys
376K    /tmp
2.6G    /usr
14G     /var
153G    total

[root@host ~]# cd /; du -sh * 2> /dev/null
0       bin
146M    boot
0       dev
23M     etc
136G    home
0       lib
0       lib64
0       media
0       mnt
24K     nginxweblog
990M    opt
0       proc
41M     root
401M    run
0       sbin
0       srv
0       sys
376K    tmp
2.6G    usr
14G     var

[root@host ~]# vgs
  VG     #PV #LV #SN Attr   VSize   VFree
  centos   1   3   0 wz--n- 931.02g    0

[root@host ~]# cd /var/log
[root@host log]# ls
anaconda       cron           dmseg      lastlog           maillog-20160201   messages-20160124  ppp              secure-20160124   spooler-20160124  yum.log
audit          cron-20160111  dmesg.old  maillog           mariadb            messages-20160201  samba            secure-20160201   spooler-20160201  yum.log-20150101
boot.log       cron-20160117  firewalld  maillog-20160111  messages           nginx              secure           spooler           tallylog          yum.log-20160101
btmp           cron-20160124  grubby     maillog-20160117  messages-20160111  ntpstats           secure-20160111  spooler-20160111  tuned
btmp-20160201  cron-20160201  httpd      maillog-20160124  messages-20160117  php-fpm            secure-20160117  spooler-20160117  wtmp

[root@host ~]# du -csh /var/*
0       /var/adm
1.3M    /var/cache
0       /var/crash
36K     /var/db
0       /var/empty
0       /var/games
0       /var/gopher
0       /var/kerberos
13G     /var/lib
0       /var/local
0       /var/lock 
90M     /var/log
0       /var/mail
0       /var/nis
0       /var/opt
0       /var/preserve
0       /var/run
51M     /var/spool
4.0K    /var/tmp
0       /var/var
4.0K    /var/www
0       /var/yp
14G     total

[root@host andi]# du -csh /var/lib/*
64K     /var/lib/alternatives
8.0K    /var/lib/authconfig
0       /var/lib/cs
0       /var/lib/dav
0       /var/lib/dbus
0       /var/lib/dhclient
0       /var/lib/dnsmasq
0       /var/lib/games
0       /var/lib/initial-setup
0       /var/lib/initramfs
4.0K    /var/lib/logrotate.status
0       /var/lib/misc
13G     /var/lib/mysql
8.0K    /var/lib/NetworkManager
40K     /var/lib/nginx
0       /var/lib/ntp
0       /var/lib/os-prober
320K    /var/lib/pear
64K     /var/lib/php
0       /var/lib/phpMyAdmin
4.0K    /var/lib/plymouth
0       /var/lib/polkit-1
4.0K    /var/lib/postfix
4.0K    /var/lib/rhsm
58M     /var/lib/rpm
0       /var/lib/rpm-state
4.0K    /var/lib/rsyslog
0       /var/lib/samba
0       /var/lib/stateless
16K     /var/lib/systemd
0       /var/lib/tpm
0       /var/lib/udisks2
0       /var/lib/upower
0       /var/lib/virtuoso
13M     /var/lib/yum
13G     total