Tomcat 集群时上传文件时如何使得多部tomcat中的文件同步，Linux下可以通过NFS来解决这个问题。可以在一部linux server上配置NFS服务器，其他linux server当作NFS客户端。

客户端只需用nfs挂载服务端的目录即可，如：

mount -t nfs 192.168.1.80:/usr/local/share/tomcat/VOS/sharefolder /usr/share/tomcat/VOS/sharefolder
或者可以在/etc/fstab中設置192.168.1.80:/usr/local/share/tomcat/VOS/sharefolder /usr/share/tomcat/VOS/sharefolder nfs defaults 0 0

其中第一个sharefolder是服务器上目录，第二个目录是客户机挂载目录

[root@master ~]# 
yum -y install nfs-utils
[root@master ~]#  vi /etc/idmapd.conf
# line 5: uncomment and change to your domain name
Domain =  server.world
[root@master ~]#  vi /etc/exports
# write like below *note
/home 10.0.0.0/24(rw,sync,no_root_squash,no_all_squash)
# *note
/home  ⇒ shared directory
10.0.0.0/24  ⇒ range of networks NFS permits accesses
rw  ⇒ writable
sync  ⇒ synchronize
no_root_squash  ⇒ enable root privilege
no_all_squash ⇒ enable users' authority
[root@master ~]#

systemctl start rpcbind.service

[root@master ~]#

systemctl start nfs-server.service

[root@master ~]#

systemctl start nfs-lock.service

[root@master ~]#

systemctl start nfs-idmap.service

[root@master ~]#

systemctl enable rpcbind.service

[root@master ~]#

systemctl enable nfs-server.service

[root@master ~]#

systemctl enable nfs-lock.service

[root@master ~]#

systemctl enable nfs-idmap.service

[root@www ~]#  yum -y install nfs-utils
[root@master ~]#  vi /etc/idmapd.conf
# line 5: uncomment and change to your domain name
Domain =  server.world
[root@www ~]#  systemctl start rpcbind.service 
[root@www ~]#  systemctl start nfs-lock.service 
[root@www ~]#  systemctl start nfs-idmap.service 
[root@www ~]#  systemctl start netfs.service 
[root@www ~]#  systemctl enable rpcbind.service 
[root@www ~]#  systemctl enable nfs-lock.service 
[root@www ~]#  systemctl enable nfs-idmap.service 
[root@www ~]#  systemctl enable netfs.service 
[root@www ~]#  mount -t nfs master.server.world:/home /home 
[root@www ~]#  df -h

Filesystem                    Size  Used Avail Use% Mounted on
rootfs                         16G  832M   14G   6% /
devtmpfs                      995M     0  995M   0% /dev
tmpfs                        1003M     0 1003M   0% /dev/shm
tmpfs                        1003M   39M  964M   4% /run
/dev/mapper/VolGroup-lv_root   16G  832M   14G   6% /
tmpfs                        1003M   39M  964M   4% /run
tmpfs                        1003M     0 1003M   0% /sys/fs/cgroup
tmpfs                        1003M     0 1003M   0% /media
/dev/vda2                     485M   32M  428M   7% /boot
master.server.world:/home/     16G  848M   14G   6% /home
# home directory on NFS is mounted
[root@www ~]#  vi /etc/fstab
/dev/mapper/VolGroup-lv_root /                       ext4    defaults  1 1
UUID=65ec32e2-f459-4d63-b8b0-e18124b50f3a /boot      ext4    defaults  1 2
/dev/mapper/VolGroup-lv_swap swap                    swap    defaults  0 0
# add at the lat line: change home directory this server mounts to the one on NFS

master.server.world:/home /home                      nfs     defaults  0 0