199上一道题，帮忙分析一下

哇哈哈

While attempting to write a 200 MB file to the /user/data file system with 1 GB
free space, the system responds with the message that it is out of space.
Which of the following could be causing this?

df output
Filesystem 1024-blocks Free %Used Iused %Iused Mounted on
/dev/hd4 40960 3744 91% 2416 12% /
/dev/hd2 1003520 35280 97% 37596 13% /usr
/dev/hd9var 36864 24540 34% 1236 14% /var
/dev/hd3 167936 8108 96% 844 2% /tmp
/dev/hd1 40960 20232 51% 1364 14% /home
/dev/datalv 1224704 1023952 16% 6309 7% /user/data
/dev/datalv2 16384 5884 65% 1018 25% /data2
/dev/userlv2 12288 11608 6% 49 2% /user2
/dev/userlv 12288 5002 59% 643 7% /user
/dev/foolv 12288 121 99% 49 2% /foo

A. The /user/data file system is mounted read only.
B. The permissions on the /user file system is wrong.
C. The permissions on the /user/data file system is wrong.
D. /user is preventing you from reaching the /user/data file system.


答案是D

哇哈哈

顶一下

java_aix

你在/user下又建了一个FS,此FS是不可见的！
所以是D!

哇哈哈

系统是允许文件系统装载到各级目录中的啊，所以这种解释不好吧？

java_aix

Mounting a file system over an existing file system
If a file system is mounted over a directory (called a mount point) held in another
file system, beneath the mount point hierarchy in the mounted-over file system,
the original file system data is hidden by the newly mounted file system. The
originally mounted file system’s data will be unavailable for use.
An example of where you would over mount is in a development environment
where you are working with different levels of the same code and do not wish to
change your make files. In the next example, there are two logical volumes,
lvol01 and lvol02. The file system on lvol01 is mounted on /filesys01, and the file
system on lvol02 is not yet mounted:
# mount
node mounted mounted over vfs date options
-------- --------------- --------------- ------ ------------ ------------
/dev/hd4 / jfs Jun 11 16:41 rw,log=/dev/hd8
/dev/hd2 /usr jfs Jun 11 16:41 rw,log=/dev/hd8
/dev/hd9var /var jfs Jun 11 16:41 rw,log=/dev/hd8
/dev/hd3 /tmp jfs Jun 11 16:41 rw,log=/dev/hd8
/dev/hd1 /home jfs Jun 11 16:42 rw,log=/dev/hd8
/dev/lv00 /usr/welcome_arcade jfs Jun 11 16:42
rw,log=/dev/hd8
/dev/lv01 /usr/welcome jfs Jun 11 16:42 rw,log=/dev/hd8
/dev/lvol01 /filsys01 jfs Jun 14 13:31
rw,log=/dev/loglv00
If a listing of the mounted file system filsys01 is done, the directory containing
data fs1dir is displayed:
# ls -l filsys01
total 16
drwxr-sr-x 20 root sys 2560 Jun 14 13:32 fs1dir
drwxrwx--- 2 root system 512 Jun 14 13:28 lost+found
Chapter 5. Disks and file systems 113
If the file system on logical volume lvol02 is now mounted over the same mount
point as that of lvol01:
# mount /dev/lvol02 /filsys01
When checked it can be noted that both file systems are still shown as being
mounted:
# mount
node mounted mounted over vfs date options
-------- --------------- --------------- ------ ------------ ------------
/dev/hd4 / jfs Jun 11 16:41 rw,log=/dev/hd8
/dev/hd2 /usr jfs Jun 11 16:41 rw,log=/dev/hd8
/dev/hd9var /var jfs Jun 11 16:41 rw,log=/dev/hd8
/dev/hd3 /tmp jfs Jun 11 16:41 rw,log=/dev/hd8
/dev/hd1 /home jfs Jun 11 16:42 rw,log=/dev/hd8
/dev/lv00 /usr/welcome_arcade jfs Jun 11 16:42
rw,log=/dev/hd8
/dev/lv01 /usr/welcome jfs Jun 11 16:42 rw,log=/dev/hd8
/dev/lvol01 /filsys01 jfs Jun 14 13:31
rw,log=/dev/loglv00
/dev/lvol02 /filsys01 jfs Jun 14 13:44
rw,log=/dev/loglv01
If a listing of the mounted file system filsys01 is done, the directory containing
data fs2dir is displayed:
# ls -l /filsys01
total 32
drwxr-sr-x 5 root sys 9728 Jun 14 13:37 fs2dir
drwxrwx--- 2 root system 512 Jun 14 13:28 lost+found
The way to fix this is to unmount the logical volume lvol02 and then mount it on a
new mount point:
# umount /dev/lvol02
Once unmounted, the data on lvol01 will be available again, as it was not
overwritten:
# mount
node mounted mounted over vfs date options
-------- --------------- --------------- ------ ------------ ------------
/dev/hd4 / jfs Jun 11 16:41 rw,log=/dev/hd8
/dev/hd2 /usr jfs Jun 11 16:41 rw,log=/dev/hd8
/dev/hd9var /var jfs Jun 11 16:41 rw,log=/dev/hd8
/dev/hd3 /tmp jfs Jun 11 16:41 rw,log=/dev/hd8
/dev/hd1 /home jfs Jun 11 16:42 rw,log=/dev/hd8
/dev/lv00 /usr/welcome_arcade jfs Jun 11 16:42
rw,log=/dev/hd8
/dev/lv01 /usr/welcome jfs Jun 11 16:42 rw,log=/dev/hd8
/dev/lvol01 /filsys01 jfs Jun 14 13:31
rw,log=/dev/loglv00
# ls -l /filsys01
total 16
drwxr-sr-x 20 root sys 2560 Jun 14 13:32 fs1dir
drwxrwx--- 2 root system 512 Jun 14 13:28 lost+found

ok?understand?

哇哈哈

我想这并不是问题的原因，java_aix你所说的是如果文件系统装载到一个非空目录中，那么此目录中的文件将不可见，等卸载后文件又显示。而这个问题并不是这样的。这个问题是把一个文件系统装载到另一个文件系统下的一个目录中，我想是这样的，继续讨论，OK？

哇哈哈

再顶一下
是太简单没有人回答，还是不想回答？老哥们啊，行行好吧，嘿嘿

哇哈哈

再顶一下
是太简单没有人回答，还是不能回答？老哥们啊，行行好吧，嘿嘿

badbone

应该是D
aix redbook 199 page 170
When a file system is mounted over a directory, the permissions of the root directory of the mounted file system take precedence over the permissions of the mount point.
/user的目录空间不够吧，不知道对不对

哇哈哈

应该没有目录空间这一说,再说/user/data的权限应该覆盖原来装载点的权限吧?