Check out the supported file system formats for CentOS 7
[root@centos-01 ~]# cat /etc/filesystems
xfs
ext4
ext3
ext2
nodev proc
nodev devpts
iso9660
vfat
hfs
hfsplus
*
mount to view the file system format of the partition
[root@centos-01 ~]# mount
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime,seclabel)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
devtmpfs on /dev type devtmpfs (rw,nosuid,seclabel,size=490008k,nr_inodes=122502,mode=755)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,seclabel)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,seclabel,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,nodev,seclabel,mode=755)
tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,seclabel,mode=755)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/usr/lib/systemd/systemd-cgroups-agent,name=systemd)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
cgroup on /sys/fs/cgroup/hugetlb type cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb)
cgroup on /sys/fs/cgroup/pids type cgroup (rw,nosuid,nodev,noexec,relatime,pids)
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event)
cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpuacct,cpu)
cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_prio,net_cls)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
configfs on /sys/kernel/config type configfs (rw,relatime)
/dev/sda3 on / type xfs (rw,relatime,seclabel,attr2,inode64,noquota)
selinuxfs on /sys/fs/selinux type selinuxfs (rw,relatime)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=26,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=12742)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,seclabel)
mqueue on /dev/mqueue type mqueue (rw,relatime,seclabel)
/dev/sda1 on /boot type xfs (rw,relatime,seclabel,attr2,inode64,noquota)
tmpfs on /run/user/0 type tmpfs (rw,nosuid,nodev,relatime,seclabel,size=99972k,mode=700)
It can be found that the "/" root directory and the "/boot" directory are in xfs format (the default file system format of CentOS 7 is xfs). In CentOS 6 and earlier versions, the ext file system format is used, CentOS 6 is ext4 format, and CentOS 5 is ext3 format.
Create partition
[root@centos-01 ~]# fdisk -l
磁盘 /dev/sda:32.2 GB, 32212254720 字节,62914560 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理):512 字节 / 512 字节
I/O 大小(最小/最佳):512 字节 / 512 字节
磁盘标签类型:dos
磁盘标识符:0x000d9f36
设备 Boot Start End Blocks Id System
/dev/sda1 * 2048 411647 204800 83 Linux
/dev/sda2 411648 4605951 2097152 82 Linux swap / Solaris
/dev/sda3 4605952 62914559 29154304 83 Linux
磁盘 /dev/sdb:10.7 GB, 10737418240 字节,20971520 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理):512 字节 / 512 字节
I/O 大小(最小/最佳):512 字节 / 512 字节
磁盘标签类型:dos
磁盘标识符:0x59b95324
设备 Boot Start End Blocks Id System
[root@centos-01 ~]# fdisk /dev/sdb
欢迎使用 fdisk (util-linux 2.23.2)。
更改将停留在内存中,直到您决定将更改写入磁盘。
使用写入命令前请三思。
命令(输入 m 获取帮助):n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
分区号 (1-4,默认 1):
起始 扇区 (2048-20971519,默认为 2048):
将使用默认值 2048
Last 扇区, +扇区 or +size{K,M,G} (2048-20971519,默认为 20971519):+3G
分区 1 已设置为 Linux 类型,大小设为 3 GiB
命令(输入 m 获取帮助):w
The partition table has been altered!
Calling ioctl() to re-read partition table.
正在同步磁盘。
[root@centos-01 ~]# fdisk -l
磁盘 /dev/sda:32.2 GB, 32212254720 字节,62914560 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理):512 字节 / 512 字节
I/O 大小(最小/最佳):512 字节 / 512 字节
磁盘标签类型:dos
磁盘标识符:0x000d9f36
设备 Boot Start End Blocks Id System
/dev/sda1 * 2048 411647 204800 83 Linux
/dev/sda2 411648 4605951 2097152 82 Linux swap / Solaris
/dev/sda3 4605952 62914559 29154304 83 Linux
磁盘 /dev/sdb:10.7 GB, 10737418240 字节,20971520 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理):512 字节 / 512 字节
I/O 大小(最小/最佳):512 字节 / 512 字节
磁盘标签类型:dos
磁盘标识符:0x59b95324
设备 Boot Start End Blocks Id System
/dev/sdb1 2048 6293503 3145728 83 Linux
format
mkfs.ext4
Equivalent tomke2fs -t ext4
[root@centos-01 ~]# mke2fs -t ext4 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
文件系统标签=
OS type: Linux
块大小=4096 (log=2)
分块大小=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
196608 inodes, 786432 blocks
39321 blocks (5.00%) reserved for the super user
第一个数据块=0
Maximum filesystem blocks=805306368
24 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Allocating group tables: 完成
正在写入inode表: 完成
Creating journal (16384 blocks): 完成
Writing superblocks and filesystem accounting information: 完成
Here is another way to format again. Even if a partition is formatted once, it can be formatted again.
[root@centos-01 ~]# mkfs.ext4 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
文件系统标签=
OS type: Linux
块大小=4096 (log=2)
分块大小=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
196608 inodes, 786432 blocks
39321 blocks (5.00%) reserved for the super user
第一个数据块=0
Maximum filesystem blocks=805306368
24 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Allocating group tables: 完成
正在写入inode表: 完成
Creating journal (16384 blocks): 完成
Writing superblocks and filesystem accounting information: 完成
- mke2fs cannot be formatted to xfs format
[root@centos-01 ~]# mke2fs -t xfs /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
Your mke2fs.conf file does not define the xfs filesystem type.
Aborting...
- It can
mkfs.xfs
be formatted into xfs format, but because the partition has been formatted before, it needs to be formatted again with the '-f' option.
[root@centos-01 ~]# mkfs.xfs /dev/sdb1
mkfs.xfs: /dev/sdb1 appears to contain an existing filesystem (ext4).
mkfs.xfs: Use the -f option to force overwrite.
[root@centos-01 ~]# mkfs.xfs -f /dev/sdb1
meta-data=/dev/sdb1 isize=512 agcount=4, agsize=196608 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=786432, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
- View the format of the unmounted partition (/dev/sdb1 has not been mounted)
[root@centos-01 ~]# blkid /dev/sdb1
/dev/sdb1: UUID="b6615809-31bf-4a30-8a9c-6550bd8f9d1f" TYPE="xfs"
mke2fs command
- '-t': specify file system type
- '-b': Specify the block size in bytes
[root@centos-01 ~]# mke2fs -b 8192 /dev/sdb1
Warning: blocksize 8192 not usable on most systems.
mke2fs 1.42.9 (28-Dec-2013)
mke2fs: 8192-byte blocks too big for system (max 4096)
无论如何也要继续? (y,n) n
[root@centos-01 ~]# mke2fs -b 2048 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
文件系统标签=
OS type: Linux
块大小=2048 (log=1)
分块大小=2048 (log=1)
Stride=0 blocks, Stripe width=0 blocks
196608 inodes, 1572864 blocks
78643 blocks (5.00%) reserved for the super user
第一个数据块=0
Maximum filesystem blocks=538968064
96 block groups
16384 blocks per group, 16384 fragments per group
2048 inodes per group
Superblock backups stored on blocks:
16384, 49152, 81920, 114688, 147456, 409600, 442368, 802816, 1327104
Allocating group tables: 完成
正在写入inode表: 完成
Writing superblocks and filesystem accounting information: 完成
- '-m': Specifies the partition reserved size. The default is 5%.
[root@centos-01 ~]# mke2fs -m 1 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
文件系统标签=
OS type: Linux
块大小=4096 (log=2)
分块大小=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
196608 inodes, 786432 blocks
7864 blocks (1.00%) reserved for the super user
第一个数据块=0
Maximum filesystem blocks=805306368
24 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Allocating group tables: 完成
正在写入inode表: 完成
Writing superblocks and filesystem accounting information: 完成
[root@centos-01 ~]# mke2fs -m 0.1 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
文件系统标签=
OS type: Linux
块大小=4096 (log=2)
分块大小=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
196608 inodes, 786432 blocks
786 blocks (0.10%) reserved for the super user
第一个数据块=0
Maximum filesystem blocks=805306368
24 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Allocating group tables: 完成
正在写入inode表: 完成
Writing superblocks and filesystem accounting information: 完成
- The previous command does not specify the file system type, use the
blkid
command to view the formatted type after the previous command is executed.
[root@centos-01 ~]# blkid /dev/sdb1
/dev/sdb1: UUID="2b56d897-2b84-4628-aafa-319e1812210c" TYPE="ext2"
If you do not specify the file system type, it is the ext2 format.
[root@centos-01 ~]# mke2fs -t ext4 -m 0.1 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
文件系统标签=
OS type: Linux
块大小=4096 (log=2)
分块大小=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
196608 inodes, 786432 blocks
786 blocks (0.10%) reserved for the super user
第一个数据块=0
Maximum filesystem blocks=805306368
24 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Allocating group tables: 完成
正在写入inode表: 完成
Creating journal (16384 blocks): 完成
Writing superblocks and filesystem accounting information: 完成
[root@centos-01 ~]# mkfs.ext4 -m 0.1 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
文件系统标签=
OS type: Linux
块大小=4096 (log=2)
分块大小=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
196608 inodes, 786432 blocks
786 blocks (0.10%) reserved for the super user
第一个数据块=0
Maximum filesystem blocks=805306368
24 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Allocating group tables: 完成
正在写入inode表: 完成
Creating journal (16384 blocks): 完成
Writing superblocks and filesystem accounting information: 完成
- '-i<byte>': Specifies the ratio of "bytes/inode". The default is 4 blocks (block) corresponding to one inode, that is, 4*4K=16K=16384Byte / 1 inode.
[root@centos-01 ~]# mke2fs -i 8192 -t ext4 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
文件系统标签=
OS type: Linux
块大小=4096 (log=2)
分块大小=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
393216 inodes, 786432 blocks
39321 blocks (5.00%) reserved for the super user
第一个数据块=0
Maximum filesystem blocks=805306368
24 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Allocating group tables: 完成
正在写入inode表: 完成
Creating journal (16384 blocks): 完成
Writing superblocks and filesystem accounting information: 完成