磁盘卷标，也叫磁盘卷内容表（VTOC），包含：
磁盘的分区表
磁盘的卷名
各分区的分区标识(分区挂接点的描述)
各分区的分区标识（分区是否可写或可挂接）
磁盘卷标占据磁盘的第一扇区
把一个磁盘分区的步骤：
1. Type format at the prompt and press Return.
2. Choose a disk by selecting the number to the left corresponding to its description.
3. Type partition at the format prompt.
4. Type print at the partition prompt.
5. Type partition number to change the root partition.
6. Enter the new values.
7. Once you are satisfied with the partition table, label the disk.
命令prtvtoc可以显示某个磁盘的分区状况
# prtvtoc /dev/rdsk/c0t0d0s2
* /dev/rdsk/c0t0d0s2 partition map
* Dimensions:
* 512 bytes/sector
* 80 sectors/track
* 9 tracks/cylinder
* 720 sectors/cylinder
* 2500 cylinders
* 1151 accessible cylinders
* Flags:
* 1: unmountable
* 10: read-only
* First Sector Last
* Partition Tag Flags Sector Count Sector Mount Directory
0 2 00 0 41040 41039 /
1 3 01 41040 65520 106559
2 5 00 0 828720 828719
6 4 00 106560 722160 828719 /usr
