Linux创建和挂载XFS文件系统测试实践

XFS文件系统简介

维基百科关于XFS的简介如下：

XFS is a high-performance 64-bit journaling file system created by Silicon Graphics, Inc (SGI) in 1993.^[6] It was the default file system in SGI's IRIX operating system starting with its version 5.3. XFS was ported to the Linux kernel in 2001; as of June 2014, XFS is supported by most Linux distributions, some of which use it as the default file system.

XFS excels in the execution of parallel input/output (I/O) operations due to its design, which is based on allocation groups (a type of subdivision of the physical volumes in which XFS is used- also shortened to AGs). Because of this, XFS enables extreme scalability of I/O threads, file system bandwidth, and size of files and of the file system itself when spanning multiple physical storage devices. XFS ensures the consistency of data by employing metadata journaling and supporting write barriers. Space allocation is performed via extents with data structures stored in B+ trees, improving the overall performance of the file system, especially when handling large files. Delayed allocation assists in the prevention of file system fragmentation; online defragmentation is also supported. A feature unique to XFS is the pre-allocation of I/O bandwidth at a pre-determined rate; this is suitable for many real-time applications. However, this feature was supported only on IRIX, and only with specialized hardware.

A notable XFS user, NASA Advanced Supercomputing Division, takes advantage of these capabilities deploying two 300+ terabyte XFS filesystems on two SGI Altix archival storage servers, each of which is directly attached to multiple Fibre Channel disk arrays.^[7]

 

 

百度百科上关于XFS的简介：

XFS一种高性能的日志文件系统，最早于1993年，由Silicon Graphics为他们的IRIX操作系统而开发，是IRIX 5.3版的默认文件系统。2000年5月，Silicon Graphics以GNU通用公共许可证发布这套系统的源代码，之后被移植到Linux 内核上。XFS 特别擅长处理大文件，同时提供平滑的数据传输。

XFS相比于其它文件系统（ext3、ext4等）的优缺点：

XFS是高性能文件系统，由于它的高性能，XFS成为了许多企业级系统的首选，特别是有大量数据，需要结构化伸缩性和稳定性的。例如，RHEL/CentOS 7 和Oracle Linux将XFS作为默认文件系统，SUSE/openSUSE已经为XFS做了长期支持。

XFS有许多独特的性能提升功能使他从众多文件系统中脱颖而出，像可伸缩/并行 IO，元数据日志，热碎片整理，IO 暂停/恢复，延迟分配等。

XFS 文件系统有一些缺陷，例如它不能压缩，删除大量文件时性能低下

创建XFS文件系统

如果系统没有XFS系统工具集，那就必须必须安装（命令如下）：

#sudo yum install xfsprogs

其实很多Linux系统将XFS作为默认文件系统，所以无需安装，如下所示， Centos 7.3就无需安装

[root@mylnx008 ~]# more /etc/redhat-release

CentOS Linux release 7.3.1611 (Core)

创建XFS格式分区，如下测试所示， 新增了一个300多G的磁盘

[root@mylnx008 ~]# fdisk -l

Disk /dev/sdb: 323.2 GB, 323196289024 bytes, 631242752 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 /dev/sda: 33.3 GB, 33285996544 bytes, 65011712 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 label type: dos

Disk identifier: 0x000c1fec

   Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *        2048     1026047      512000   83  Linux

/dev/sda2         1026048    62914559    30944256   83  Linux

Disk /dev/sdc: 145.0 GB, 144955146240 bytes, 283115520 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 label type: dos

Disk identifier: 0x034b6e5c

   Device Boot      Start         End      Blocks   Id  System

/dev/sdc1            2048   283113471   141555712   83  Linux

[root@mylnx008 ~]# fdisk /dev/sdb

Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.

Be careful before using the write command.

Device does not contain a recognized partition table

Building a new DOS disklabel with disk identifier 0xafc7c358.

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 (2048-631242751, default 2048): 

Using default value 2048

Last sector, +sectors or +size{K,M,G} (2048-631242751, default 631242751): 

Using default value 631242751

Partition 1 of type Linux and of size 301 GiB is set

Command (m for help): w

The partition table has been altered!

Calling ioctl() to re-read partition table.

Syncing disks.

格式化分区为XFS，使用mkfs.xfs命令。如果已有其他文件系统创建在此分区，必须加上"-f"参数来覆盖它。

[root@mylnx008 ~]# mkfs.xfs -f  /dev/sdb

meta-data=/dev/sdb               isize=512    agcount=4, agsize=19726336 blks

         =                       sectsz=512   attr=2, projid32bit=1

         =                       crc=1        finobt=0, sparse=0

data     =                       bsize=4096   blocks=78905344, imaxpct=25

         =                       sunit=0      swidth=0 blks

naming   =version 2              bsize=4096   ascii-ci=0 ftype=1

log      =internal log           bsize=4096   blocks=38528, version=2

         =                       sectsz=512   sunit=0 blks, lazy-count=1

realtime =none                   extsz=4096   blocks=0, rtextents=0

[root@mylnx008 ~]# df -T /dev/sdb

Filesystem     Type     1K-blocks  Used Available Use% Mounted on

devtmpfs       devtmpfs   1746644     0   1746644   0% /dev

[root@mylnx008 ~]# 

挂载XFS文件系统

 

[root@mylnx008 ~]# mkdir /mysql

[root@mylnx008 ~]# mount  -t  xfs  /dev/sdb  /mysql

[root@mylnx008 ~]#  df -T /dev/sdb

Filesystem     Type 1K-blocks  Used Available Use% Mounted on

/dev/sdb       xfs  315467264 32944 315434320   1% /mysql

[root@mylnx008 ~]# 

[root@mylnx008 ~]# df -h

Filesystem      Size  Used Avail Use% Mounted on

/dev/sda2        30G   22G  8.2G  73% /

devtmpfs        1.7G     0  1.7G   0% /dev

tmpfs           1.7G     0  1.7G   0% /dev/shm

tmpfs           1.7G   25M  1.7G   2% /run

tmpfs           1.7G     0  1.7G   0% /sys/fs/cgroup

/dev/sda1       497M   62M  436M  13% /boot

/dev/sdc1       133G  4.2G  122G   4% /mnt/resource

tmpfs           344M     0  344M   0% /run/user/1000

/dev/sdb        301G   33M  301G   1% /mysql

上面命令只对当前环境有效，如果要在启动时自动挂载XFS分区在/mysql上，必须配置/etc/fstab配置文件

[root@mylnx008 ~]# vi /etc/fstab

#

# /etc/fstab

# Created by anaconda on Mon Sep 25 21:44:42 2017

#

# Accessible filesystems, by reference, are maintained under '/dev/disk'

# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info

#

UUID=b7559ac5-b3a4-4b00-b98a-a2a2611806d0 /                       xfs     defaults        0 0

UUID=b98659b2-5f8c-493e-9304-658905ef1391 /boot                   xfs     defaults        0 0

/dev/sdb                                  /mysql                  xfs     defaults        0 0 

当如你也可以使用UUID替换对应的设备，如下所示，先找到对应设备的UUID，然后修改/etc/fastab

[root@mylnx008 ~]# blkid  /dev/sdb

/dev/sdb: UUID="6fcc5417-3c1b-4c71-aac7-344bac7654a4" TYPE="xfs" 

[root@mylnx008 ~]# blkid  /dev/sda2

/dev/sda2: UUID="b7559ac5-b3a4-4b00-b98a-a2a2611806d0" TYPE="xfs" 

[root@mylnx008 ~]# 

[root@mylnx008 ~]# vi /etc/fstab 

#

# /etc/fstab

# Created by anaconda on Mon Sep 25 21:44:42 2017

#

# Accessible filesystems, by reference, are maintained under '/dev/disk'

# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info

#

UUID=b7559ac5-b3a4-4b00-b98a-a2a2611806d0 /                       xfs     defaults        0 0

UUID=b98659b2-5f8c-493e-9304-658905ef1391 /boot                   xfs     defaults        0 0

UUID=6fcc5417-3c1b-4c71-aac7-344bac7654a4 /mysql                  xfs     defaults        0 0  

参考资料：

https://linux.cn/article-4245-1.html