ubuntu 14.04 安装redis

root@hett-PowerEdge-T30:~# sudo apt-get install redis-server
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following extra packages will be installed:
  libjemalloc1 redis-tools
The following NEW packages will be installed:
  libjemalloc1 redis-server redis-tools
0 upgraded, 3 newly installed, 0 to remove and 76 not upgraded.
Need to get 410 kB of archives.
After this operation, 1,272 kB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://cn.archive.ubuntu.com/ubuntu/ trusty/universe libjemalloc1 amd64 3.5.1-2 [76.8 kB]
Get:2 http://cn.archive.ubuntu.com/ubuntu/ trusty/universe redis-tools amd64 2:2.8.4-2 [65.7 kB]
Get:3 http://cn.archive.ubuntu.com/ubuntu/ trusty/universe redis-server amd64 2:2.8.4-2 [267 kB]
Fetched 410 kB in 4s (92.7 kB/s)      
Selecting previously unselected package libjemalloc1.
(Reading database ... 244892 files and directories currently installed.)
Preparing to unpack .../libjemalloc1_3.5.1-2_amd64.deb ...
Unpacking libjemalloc1 (3.5.1-2) ...
Selecting previously unselected package redis-tools.
Preparing to unpack .../redis-tools_2%3a2.8.4-2_amd64.deb ...
Unpacking redis-tools (2:2.8.4-2) ...
Selecting previously unselected package redis-server.
Preparing to unpack .../redis-server_2%3a2.8.4-2_amd64.deb ...
Unpacking redis-server (2:2.8.4-2) ...
Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
Processing triggers for ureadahead (0.100.0-16) ...
Setting up libjemalloc1 (3.5.1-2) ...
Setting up redis-tools (2:2.8.4-2) ...
Setting up redis-server (2:2.8.4-2) ...
Starting redis-server: redis-server.
Processing triggers for libc-bin (2.19-0ubuntu6.14) ...
Processing triggers for ureadahead (0.100.0-16) ...
root@hett-PowerEdge-T30:~# ps -ef | grep redis
redis    26889     1  0 15:40 ?        00:00:00 /usr/bin/redis-server 127.0.0.1:6379       
root     26912 26268  0 15:41 pts/43   00:00:00 grep --color=auto redis
root@hett-PowerEdge-T30:~# ps -aux | grep redis
redis    26889  0.0  0.0  44060  6632 ?        Ssl  15:40   0:00 /usr/bin/redis-server 127.0.0.1:6379       
root     26922  0.0  0.0  15956  2480 pts/43   S+   15:41   0:00 grep --color=auto redis
root@hett-PowerEdge-T30:~# redis-cli
127.0.0.1:6379> helo
(error) ERR unknown command 'helo'
127.0.0.1:6379> help
redis-cli 2.8.4
Type: "help @<group>" to get a list of commands in <group>
      "help <command>" for help on <command>
      "help <tab>" to get a list of possible help topics
      "quit" to exit
127.0.0.1:6379> exit