为什么我用mkfs.ext4 命令格式化后，没有变成linux文件系统

[ff千雨]

我想用下面的命令把　/dev/sdb2 　格式化为　linux格式
sudo umount /dev/sdb2
sudo mkfs.ext4 /dev/sdb2
但是我运行完以后，
$blkid
/dev/sdb2: LABEL="data" UUID="F4B25A50B25A1786" TYPE="ntfs"
$sudo fdisk -l
/dev/sdb2 1024002048 2883024895 929511424 7 HPFS/NTFS/exFAT
$sudo fdisk -l /dev/sdb2
Disk identifier: 0x00000000
Disk /dev/sdb2 doesn't contain a valid partition table

[jxhow]

格式化之前，卸载分区

代码： 全选

sudo umount /dev/sdb2

[ff千雨]

格式化之前，卸载分区

代码： 全选

sudo umount /dev/sdb2

我当然卸载了分区，格式已经进行了。盘内的东西都没了。但是，还是显示为ntsf.
是不是应该先把　fdisk　转换为linux分区后，再格式化

[zhw2101024]

格式化的命令输出是什么？

[ff千雨]

格式化的命令输出是什么？

xueyansong@xueyansong-Lenovo:/home$ sudo mkfs.ext4 /dev/sdb2
mke2fs 1.42 (29-Nov-2011)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
58097664 inodes, 232377856 blocks
11618892 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
7092 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
102400000, 214990848

Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

800G的分区，几秒钟就完事儿了，一定有问题。

[ff千雨]

知道了，好像应该用　fdisk -t 想把　/dev/sdb2 改成　83

[jtshs256]

跟格式化有虾米关系……类型写在分区表里的啊……

[ff千雨]

现在好了，但是有个问题

Partition 3 does not start on physical sector boundary.
查了些英文资料，好像说也不是什么大问题，但有可能会造成数据丢失。
如果造成数据丢失，丢失sdb2的，还是sdb3的？　　
是怎么回事？
----------------------------------------------------------------------------------------
xueyansong@xueyansong-Lenovo:/media$ sudo fdisk -l

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 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: 0x3e2c9b7c

Device Boot Start End Blocks Id System
/dev/sda1 2048 206847 102400 7 HPFS/NTFS/exFAT
/dev/sda2 * 206848 307406847 153600000 7 HPFS/NTFS/exFAT
/dev/sda3 307406848 913704959 303149056 f W95 Ext'd (LBA)
/dev/sda4 913704960 976773167 31534104 12 Compaq diagnostics
/dev/sda5 307408896 913704959 303148032 7 HPFS/NTFS/exFAT

Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x0bcba3db

Device Boot Start End Blocks Id System
/dev/sdb1 * 2048 1024002047 512000000 7 HPFS/NTFS/exFAT
/dev/sdb2 1024002048 2883024895 929511424 83 Linux
/dev/sdb3 2883026942 3907028991 512001025 5 Extended
Partition 3 does not start on physical sector boundary.
/dev/sdb5 2883026944 2892789759 4881408 82 Linux swap / Solaris
/dev/sdb6 2892791808 2893766655 487424 83 Linux
/dev/sdb7 2893768704 3907028991 506630144 83 Linux