linux挂载光盘

[root@node2 /]# ls -l /dev |grep cdrom
lrwxrwxrwx 1 root root           3 Dec  4 03:17 cdrom2 -> sr0
crw-rw---- 1 root cdrom    21,   1 Dec  4 03:17 sg1
brw-rw---- 1 root cdrom    11,   0 Dec  4 03:17 sr0
[root@node2 /]# mount /dev/sr0 /mnt
mount: block device /dev/sr0 is write-protected, mounting read-only
[root@node2 /]# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda3        45G   19G   25G  43% /
tmpfs           931M     0  931M   0% /dev/shm
/dev/sda1       283M   39M  229M  15% /boot
/dev/sr0        3.7G  3.7G     0 100% /mnt