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
注意：若防火墙开着，要让nfs程序通过防火墙
