sd卡重新分区以及格式化

参考

备份SD卡镜像

裁剪
裁剪
这是备份了整张SD卡（SD卡多大，拷贝出来的镜像就有多大，也可以进行裁剪）
sudo dd if=/dev/sdb of=xxxx.img bs=8M

挂载

查看SD卡挂挂载点：

df -T
# (-h可以查看单位为M的大小)

卸载SD卡：

sudo umount /dev/sdb1 /dev/sdb2

使用fdisk工具删除分区、添加分区：

sudo fdisk /dev/sdb

输入m 帮助：

Command (m for help): m
Command action
   a   toggle a bootable flag
   b   edit bsd disklabel
   c   toggle the dos compatibility flag
   d   delete a partition
   l   list known partition types
   m   print this menu
   n   add a new partition
   o   create a new empty DOS partition table
   p   print the partition table
   q   quit without saving changes
   s   create a new empty Sun disklabel
   t   change a partition's system id
   u   change display/entry units
   v   verify the partition table
   w   write table to disk and exit
   x   extra functionality (experts only)

输入p查看当前sd卡的分区(partition)信息：

Command (m for help): p
 
Disk /dev/sdb: 7948 MB, 7948206080 bytes
245 heads, 62 sectors/track, 1021 cylinders, total 15523840 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
 
   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *        2048     1048576      523264+   c  W95 FAT32 (LBA)
/dev/sdb2         1048577    15523839     7237631+  83  Linux

删除分区

输入d删除(delete)所有sd卡分区。因为有2个分区，需要删除2次

Command (m for help): d
Partition number (1-4): 1
 
Command (m for help): d
Selected partition 2

建立分区

输入n新建(new)一个分区

输入p选择新建一个主分区

输入1创建分区1

输入分区1的‘First sector’和‘Last sector’

Command (m for help): n
Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended
Select (default p): p
Partition number (1-4, default 1): 1
First sector (2048-15523839, default 2048): 2048
Last sector, +sectors or +size{ 
   K,M,G} (2048-15523839, default 15523839): 
Using default value 15523839

输入w将建立完成对分区表写入sd卡，并退出

Command (m for help): w
The partition table has been altered!
 
Calling ioctl() to re-read partition table.
 
WARNING: If you have created or modified any DOS 6.x
partitions, please see the fdisk manual page for additional
information.
Syncing disks.

格式化分区

格式化 fat 分区（windows下可见）：

sudo mkfs.vfat -F 32 -n boot /dev/sdb1

格式化 ext3 分区：

sudo mkfs.ext3 -L rootfs /dev/sdb2

fat分区存放内核、设备树等。ext3分区存放根文件系统。

今天的文章sd卡重新分区以及格式化分享到此就结束了，感谢您的阅读。