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因为FUSE可以让你以任何奇怪的方式安装文件系统，理所当然地，用户安装FUSE客户端文件系统的能力也必须受到用户所在组权限的限制。下面是一个例子，在一开始，用户没有安装文件系统的权限，被拒绝安装。然后，我将自己加入到相应的用户组后重新登录，初始的MySQLfs文件系统和数据库都是空的，使用df命令可以显示内核已经知道被安装的文件系统。在例子的结尾，fusermount命令将用户创建的FUSE文件系统卸载了。
$ mkdir ~/mysqlfs
$ mysqlfs -ohost=localhost -odatabase=mysqlfs ~/mysqlfs
* Opening logfile 'mysqlfs.log': OK
fuse: failed to open /dev/fuse: Permission denied
$ su -l
root# usermod -a -G fuse ben
root# exit
$ exit
...
$ id
uid=500(ben) gid=500(ben) groups=492(fuse), ...
$ mysqlfs -ohost=localhost -odatabase=mysqlfs ~/mysqlfs
* Opening logfile 'mysqlfs.log': OK
$ ls -ld mysqlfs
drwxr-xr-x 1 root root 0 2008-01-24 16:24 mysqlfs
$ df -h mysqlfs .
Filesystem Size Used Avail Use% Mounted on
mysqlfs 0 0 0 - /home/ben/mysqlfs
/dev/sdc3 16G 4.4G 11G 31% /home
$ ls -l mysqlfs
total 0
$ fusermount -u mysqlfs
既然我们已经拥有权限，可以将MySQL安装为FUSE文件系统，接下来，让我们复制一些文件到MySQL数据库中，使之与文件系统相结合。在下面的例子中，我将项目Gutenberg的一些文本文件复制到MySQLfs并验证它们在读取的时候，与原始文件有同样的MD5返回值。然后，我将Linux文件tarbar复制到MySQLfs，想看看MySQLfs是如何处理一个44M文件的。
通过冷磁盘高速缓存将内核从/tmp目录备份到/tmp目录需要花2秒，而将之复制到MySQLfs将花费20秒，为了利用磁盘中的缓存，马上将上述操作再次执行，/tmp目录下的备份花费0.3秒,而复制到MySQLfs中依旧花费20秒。这说明，写操作是MySQLfs的主要瓶颈。当读取内核的时候，MySQLfs似乎缓存了一些数据，这使得响应时间大大快于其他测试。如果你的文件系统经常用到读操作，则MySQLfs将是一个有意思的选择，因为MySQLfs的缓存可以派上用场。
~]$ cp -av /.../guten ./mysqlfs/
`/.../guten' -> `./mysqlfs/guten'
`/.../guten/alice13a.txt' -> `./mysqlfs/guten/alice13a.txt'
`/.../guten/boysw10.txt' -> `./mysqlfs/guten/boysw10.txt'
`/.../guten/dmoro11.txt' -> `./mysqlfs/guten/dmoro11.txt'
~]$ cd ~/mysqlfs/guten
guten]$ ls -l
-rw-r----- 1 ben ben 153477 2008-01-12 13:23 alice13a.txt
-rw-rw---- 1 ben ben 48923 2008-01-12 13:23 boysw10.txt
-rw-rw---- 1 ben ben 259214 2008-01-12 13:23 dmoro11.txt
guten]$ md5sum *
135e06ad31b169065bccbf03ec7236f2 alice13a.txt
7dd30f1b37e32cdb5d21fe992bbf248d boysw10.txt
87c05f11193c0e05b3d0dec0808a0450 dmoro11.txt
guten]$ md5sum /.../guten/*
135e06ad31b169065bccbf03ec7236f2 /.../guten/alice13a.txt
7dd30f1b37e32cdb5d21fe992bbf248d /.../guten/boysw10.txt
87c05f11193c0e05b3d0dec0808a0450 /.../guten/dmoro11.txt
guten]$ cd ..
mysqlfs]$ time cp /tmp/linux-2.6.23.tar.bz2 .
real 0m16.278s
user 0m0.006s
sys 0m0.531s
mysqlfs]$ time cat linux-2.6.23.tar.bz2 >/dev/null
real 0m0.502s
user 0m0.004s
sys 0m0.035s
mysqlfs]$ time dd if=linux-2.6.23.tar.bz2 of=/tmp/junk bs=1024 count=1024
1048576 bytes (1.0 MB) copied, 0.0200973 s, 52.2 MB/s
real 0m0.058s
user 0m0.003s
sys 0m0.013s
mysqlfs]$ time dd if=linux-2.6.23.tar.bz2 of=/tmp/junk bs=1024 count=1024 skip=9000
1048576 bytes (1.0 MB) copied, 0.0214207 s, 49.0 MB/s
real 0m0.031s
user 0m0.001s
sys 0m0.011s
虽然被很多人所不齿，但我还是决定在Bonnie++文件系统下使用MySQLfs。我通过虚拟机进行了这些测试，由于是在虚拟机中，性能可能会呈线性下降，但由于MySQL数据库和/tmp目录存储于同一虚拟硬盘上，其性能比还是有效的。
在如下的结果中，你能看到，在运行Bonnie++ (version 1.03a-7)时，MySQLfs的速度是/tmp/bonnie (ext3)的十分之一。这说明，我们并不太想使用MySQLfs来直接存储邮件目录。Bonnie++被设计成适合在本地内核文件系统上工作而非FUSE，这种定位非常适用于大行文件的读写。
$ /usr/sbin/bonnie++ -d /tmp/bonnie
Version
1.03
------Sequential Output------ --Sequential Input- --Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine
Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP
/sec %CP
v8tsrv
2G 18155
31 16726
5 13338
6 26207
46 74527
24
9840 144
------Sequential Create------ --------Random Create--------
-Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files
/sec %CP
/sec %CP
/sec %CP
/sec %CP
/sec %CP
/sec %CP
16 24878
94 +++++ +++ +++++ +++ 29018
99 +++++ +++ +++++ +++
$ /usr/sbin/bonnie++ -d ~/mysqlfs/bonnie
Version
1.03
------Sequential Output------ --Sequential Input- --Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine
Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP
/sec %CP
v8tsrv
2G
2615
5
1207
1
1323
1
2143
2
2363
0 138.1
0
------Sequential Create------ --------Random Create--------
-Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files
/sec %CP
/sec %CP
/sec %CP
/sec %CP
/sec %CP
/sec %CP
16
186
2
505
1
296
2
209
2
441
1
282
2
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