我希望有人能帮助我找出问题，或者至少给我指明正确的方向。
我在 FreeNAS 上创建了一个 NFS 共享。该服务器有一个外部 IP。我可以使用以下命令将其挂载到我的 Debian 计算机（位于本地网络上）：
mount -t nfs 1.2.3.4:/mnt/backup /mnt/backup
我无法从 XenServer 机器或 Dom0 上的任何 VM 安装此程序。我已经用尽了 Google 搜索能力。以下是我正在运行的命令和详细返回。非常感谢您的帮助！谢谢
mount -v -t nfs -o tcp 1.1.1.1:/mnt/backup /mnt/backup
mount.nfs: timeout set for Sat Apr 12 16:51:43 2014
mount.nfs: trying text-based options 'tcp,vers=4,addr=1.1.1.1,clientaddr=2.2.2.2'
mount.nfs: mount(2): Protocol not supported
mount.nfs: trying text-based options 'tcp,addr=1.1.1.1'
mount.nfs: prog 100003, trying vers=3, prot=6
mount.nfs: trying 1.1.1.1 prog 100003 vers 3 prot TCP port 2049
mount.nfs: prog 100005, trying vers=3, prot=6
mount.nfs: trying 1.1.1.1 prog 100005 vers 3 prot TCP port 790
mount.nfs: portmap query failed: RPC: Remote system error - Connection timed out
mount.nfs: trying text-based options 'tcp,vers=4,addr=1.1.1.1,clientaddr=2.2.2.2