我无法在我的 Ubuntu 14.10 服务器上安装 ACL（参见输出）。
david@server:/mnt/storagedata$ sudo apt-get install acl
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed
acl
0 to upgrade, 1 to newly install, 0 to remove and 0 not to upgrade.
Need to get 0 B/43.8 kB of archives.
After this operation, 197 kB of additional disk space will be used.
david@server:/mnt/storagedata$ setfacl
The program 'setfacl' is currently not installed. You can install it by typing:
sudo apt-get install acl
david@server:/mnt/storagedata$
如您所见，该命令并未安装 ACL。
额外信息：
david@server:/mnt/storagedata$ sudo uname -a
Linux server 3.16.0-43-generic #58~14.04.1-Ubuntu SMP Mon Jun 22 10:21:20 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
如何安装 ACL？