每日一指令（mount）_/dev/sr0 already mounted on

mount 挂载

debian中挂载光盘。

root@debian-daniel:/home/keep# mount /dev/cdrom /media/cdrom
mount: block device /dev/sr0 is write-protected, mounting read-only
mount: /dev/sr0 already mounted or /media/cdrom busy
mount: according to mtab, /dev/sr0 is already mounted on /media/cdrom0
  

具体如上。

umount /media/cdrom

Usage: mount -V                 : print version
       mount -h                 : print this help
       mount                    : list mounted filesystems
       mount -l                 : idem, including volume labels
So far the informational part. Next the mounting.
The command is `mount [-t fstype] something somewhere'.
Details found in /etc/fstab may be omitted.
       mount -a [-t|-O] ...     : mount all stuff from /etc/fstab
       mount device             : mount device at the known place
       mount directory          : mount known device here
       mount -t type dev dir    : ordinary mount command
Note that one does not really mount a device, one mounts
a filesystem (of the given type) found on the device.
One can also mount an already visible directory tree elsewhere:
       mount --bind olddir newdir
or move a subtree:
       mount --move olddir newdir
One can change the type of mount containing the directory dir:
       mount --make-shared dir
       mount --make-slave dir
       mount --make-private dir
       mount --make-unbindable dir
One can change the type of all the mounts in a mount subtree
containing the directory dir:
       mount --make-rshared dir
       mount --make-rslave dir
       mount --make-rprivate dir
       mount --make-runbindable dir
A device can be given by name, say /dev/hda1 or /dev/cdrom,
or by label, using  -L label  or by uuid, using  -U uuid .
Other options: [-nfFrsvw] [-o options] [-p passwdfd].

忽然发现一天理解一个指令都有困难，只能浅显地知道有这么一回事吧。