ubuntu中，virturalbox 点开始报错

错误信息如下：

Failed to load VMMR0.r0 (VERR_SUPLIB_WORLD_WRITABLE).
Unknown error creating VM (VERR_SUPLIB_WORLD_WRITABLE).

Result Code: NS_ERROR_FAILURE (0x80004005)
Component: Console
Interface: IConsole {515e8e8d-f932-4d8e-9f32-79a52aead882}


[czmmiao@czmmiao Logs]$ cat VBox.log
00:00:00.460 VirtualBox 4.0.0 r69151 linux.x86 (Dec 22 2010 16:32:27) release log
00:00:00.460 Log opened 2011-02-08T02:38:09.654597000Z
00:00:00.461 OS Product: Linux
00:00:00.461 OS Release: 2.6.35.10-74.fc14.i686
00:00:00.461 OS Version: #1 SMP Thu Dec 23 16:17:40 UTC 2010
00:00:00.461 DMI Product Name: 2743AWC
00:00:00.461 DMI Product Version: ThinkPad SL
00:00:00.462 Host RAM: 3023MB RAM, available: 2404MB
00:00:00.462 Executable: /usr/lib/virtualbox/VirtualBox
00:00:00.462 Process ID: 7364
00:00:00.462 P ackage type: LINUX_32BITS_FEDORA_14
00:00:00.488 pdmR3LoadR0U: pszName="VMMR0.r0" rc=VERR_SUPLIB_WORLD_WRITABLE szErr="World writable: '/usr'"
00:00:00.488 VMSetError: /home/vbox/vbox-4.0.0/src/VBox/VMM/VM.cpp(579) int vmR3CreateU(UVM*, uint32_t, int (*)(VM*, void*), void*); rc=VERR_SUPLIB_WORLD_WRITABLE
00:00:00.488 VMSetError: Failed to load VMMR0.r0
00:00:00.488 VMSetError: /home/vbox/vbox-4.0.0/src/VBox/VMM/VM.cpp(350) int VMR3Create(uint32_t, const VMM2USERMETHODS*, void (*)(VM*, void*, int, const char*, unsigned int, const char*, const char*, char*), void*, int (*)(VM*, void*), void*, VM**); rc=VERR_SUPLIB_WORLD_WRITABLE
00:00:00.488 VMSetError: Unknown error creating VM
00:00:00.488 ERROR [COM]: aRC=NS_ERROR_FAILURE (0x80004005) aIID={515e8e8d-f932-4d8e-9f32-79a52aead882} aComponent={Console} aText={Failed to load VMMR0.r0 (VERR_SUPLIB_WORLD_WRITABLE).
00:00:00.488 Unknown error creating VM (VERR_SUPLIB_WORLD_WRITABLE)}, preserve=false
00:00:00.502 Power up failed (vrc=VERR_SUPLIB_WORLD_WRITABLE, rc=NS_ERROR_FAILURE (0X80004005))

其中重要的一句：

00:00:00.488 pdmR3LoadR0U: pszName="VMMR0.r0" rc=VERR_SUPLIB_WORLD_WRITABLE szErr="World writable: '/usr'"

就是说/usr目录的可写权限放的太宽了。网上说如下操作即可：

sudo chmod o-w /usr

但是我这样做以后还是报错，我想了想，又执行了以下语句就可以了：

sudo chmod -R o-w /usr

即递归的将/usr目录下的所有文件都去掉了其它人的可写权限