XFS是擴展性高、高性能的文件系統。也是rhel7/centos7的默認文件系統。XFS支持metadata journaling,這使其能從crash中更快速的恢復。它也支持在掛載和活動的狀態下進行碎片整理和擴容。通過延遲分配，XFS 贏得了許多機會來優化寫性能。可通過工具xfsdump和xfsrestore來備份和恢復xfs文件系統，xfsdump可使用dump級別來完成增量備份，還可通過size,subtree,inode flags來排除文件。也支持user、group、PRoject配額。

下面將介紹如何創建xfs文件系統，分配配額以及對其擴容:###############################################################################將/dev/sdb分區（2G），并啟動LVM功能

[root@localhost zhongq]#parted /dev/sdb                               GNU Parted 3.1Using /dev/sdbWelcome to GNU Parted! Type 'help' to view a list of commands.(parted) mkpart primary 4 2048(parted) set 1 lvm on                                                    (parted) p                                                             Model: VMware, VMware Virtual S (scsi)Disk /dev/sdb: 2147MBSector size (logical/physical): 512B/512BPartition Table: gptDisk Flags: Number  Start   End     Size    File system  Name     Flags 1      4194kB  2048MB  2044MB               primary  lvm

###############################################################################創建PV

[root@localhost zhongq]# pvcreate /dev/sdb1  Physical volume "/dev/sdb1" successfully created[root@localhost zhongq]# pvdisplay  --- Physical volume ---  PV Name               /dev/sda2  VG Name               centos  PV Size               24.51 GiB / not usable 3.00 MiB  Allocatable           yes (but full)  PE Size               4.00 MiB  Total PE              6274  Free PE               0  Allocated PE          6274  PV UUID               9hp8U7-IJM6-bwbP-G9Vn-IVuJ-yvE8-AkFjcB     "/dev/sdb1" is a new physical volume of "1.90 GiB"  --- NEW Physical volume ---  PV Name               /dev/sdb1  VG Name                 PV Size               1.90 GiB  Allocatable           NO  PE Size               0     Total PE              0  Free PE               0  Allocated PE          0  PV UUID               bu7yIH-1440-BPy1-APG2-FpvX-ejLS-2MIlA8

###############################################################################將/dev/sdb1分配到名為xfsgroup00的VG

[root@localhost zhongq]# vgcreate  xfsgroup00 /dev/sdb1 Volume group "xfsgroup00" successfully created[root@localhost zhongq]# vgdisplay --- Volume group ---  VG Name               centos  System ID               Format                lvm2  Metadata Areas        1  Metadata Sequence No  3  VG access             read/write  VG Status             resizable  MAX LV                0  Cur LV                2  Open LV               2  Max PV                0  Cur PV                1  Act PV                1  VG Size               24.51 GiB  PE Size               4.00 MiB  Total PE              6274  Alloc PE / Size       6274 / 24.51 GiB  Free  PE / Size       0 / 0     VG UUID               T3Ryyg-R0rn-2i5r-7L5o-AZKG-yFkh-CDzhKm     --- Volume group ---  VG Name               xfsgroup00  System ID               Format                lvm2  Metadata Areas        1  Metadata Sequence No  1  VG Access             read/write  VG Status             resizable  MAX LV                0  Cur LV                0  Open LV               0  Max PV                0  Cur PV                1  Act PV                1  VG Size               1.90 GiB  PE Size               4.00 MiB  Total PE              487  Alloc PE / Size       0 / 0     Free  PE / Size       487 / 1.90 GiB  VG UUID               ejuwcc-sVES-MWWB-3Mup-n1wB-Kd0g-u7jm0H

###############################################################################使用命令lvcreate來創建xfsgroup00組大小為1G的名為xfsdata的LV

[root@localhost zhongq]# lvcreate -L 1024M -n xfsdata xfsgroup00WARNING: xfs signature detected on /dev/xfsgroup00/xfsdata at offset 0. Wipe it? [y/n] y  Wiping xfs signature on /dev/xfsgroup00/xfsdata.  Logical volume "xfsdata" created[root@localhost zhongq]# lvdisplay  --- Logical volume ---  LV Path                /dev/centos/swap  LV Name                swap  VG Name                centos  LV UUID                EnW3at-KlFG-XGaQ-DOoH-cGPP-8pSf-teSVbh  LV Write Access        read/write  LV Creation host, time localhost, 2014-08-18 20:15:25 +0800  LV Status              available  # open                 2  LV Size                2.03 GiB  Current LE             520  Segments               1  Allocation             inherit  Read ahead sectors     auto  - currently set to     8192  Block device           253:0     --- Logical volume ---  LV Path                /dev/centos/root  LV Name                root  VG Name                centos  LV UUID                zmZGkv-Ln4W-B8AY-oDnD-BEk2-6VWL-L0cZOv  LV Write Access        read/write  LV Creation host, time localhost, 2014-08-18 20:15:26 +0800  LV Status              available  # open                 1  LV Size                22.48 GiB  Current LE             5754  Segments               1  Allocation             inherit  Read ahead sectors     auto  - currently set to     8192  Block device           253:1     --- Logical volume ---  LV Path                /dev/xfsgroup00/xfsdata  LV Name                xfsdata  VG Name                xfsgroup00  LV UUID                O4yvoY-XGcD-0zPm-eilR-3JJP-updU-rRCSlJ  LV Write Access        read/write  LV Creation host, time localhost.localdomain, 2014-09-23 15:50:19 +0800  LV Status              available  # open                 0  LV Size                1.00 GiB  Current LE             256  Segments               1  Allocation             inherit  Read ahead sectors     auto  - currently set to     8192  Block device           253:3

###############################################################################格式化分區為xfs文件系統。注意：xfs被創建后，其size將無法縮小，但可以通過xfs_growfs來增大

[root@localhost zhongq]# mkfs.xfs /dev/xfsgroup00/xfsdata meta-data=/dev/xfsgroup00/xfsdata isize=256    agcount=4, agsize=65536 blks         =                       sectsz=512   attr=2, projid32bit=1         =                       crc=0data     =                       bsize=4096   blocks=262144, imaxpct=25         =                       sunit=0      swidth=0 blksnaming   =version 2              bsize=4096   ascii-ci=0 ftype=0log      =internal log           bsize=4096   blocks=2560, version=2         =                       sectsz=512   sunit=0 blks, lazy-count=1realtime =none                   extsz=4096   blocks=0, rtextents=0

###############################################################################掛載xfs系統分區到指定目錄，并通過參數uquota,gquota開啟文件系統配額。

[root@localhost zhongq]# mkdir /xfsdata[root@localhost zhongq]# mount -o uquota,gquota /dev/xfsgroup00/xfsdata /xfsdata[root@localhost zhongq]# chmod 777 /xfsdata[root@localhost zhongq]# mount|grep xfsdata/dev/mapper/xfsgroup00-xfsdata on /xfsdata type xfs (rw,relatime,attr2,inode64,usrquota,grpquota)

###############################################################################使用xfs_quota命令來查看配額信息以及為用戶和目錄分配配額，并驗證配額限制是否生效。

[root@localhost zhongq]# xfs_quota -x -c 'report' /xfsdataUser quota on /xfsdata (/dev/mapper/xfsgroup00-xfsdata)                               Blocks                     User ID          Used       Soft       Hard    Warn/Grace     ---------- -------------------------------------------------- root                0          0          0     00 [--------]Group quota on /xfsdata (/dev/mapper/xfsgroup00-xfsdata)                               Blocks                     Group ID         Used       Soft       Hard    Warn/Grace     ---------- -------------------------------------------------- root                0          0          0     00 [--------][root@localhost zhongq]# xfs_quota -x -c 'limit bsoft=100M bhard=120M zhongq' /xfsdata[root@localhost zhongq]#xfs_quota -x -c 'report' /xfsdataUser quota on /xfsdata (/dev/mapper/xfsgroup00-xfsdata)                               Blocks                     User ID          Used       Soft       Hard    Warn/Grace     ---------- -------------------------------------------------- root                0          0          0     00 [--------]zhongq              0     102400     122880     00 [--------]Group quota on /xfsdata (/dev/mapper/xfsgroup00-xfsdata)                               Blocks                     Group ID         Used       Soft       Hard    Warn/Grace     ---------- -------------------------------------------------- root                0          0          0     00 [--------][root@localhost zhongq]# su zhongq[zhongq@localhost ~]$ dd if=/dev/zero of=/xfsdata/zq00 bs=1M count=100100+0 records in100+0 records out104857600 bytes (105 MB) copied, 28.9833 s, 3.6 MB/s[zhongq@localhost ~]$ dd if=/dev/zero of=/xfsdata/zq01 bs=1M count=100dd: error writing ‘/xfsdata/zq01’: Disk quota exceeded21+0 records in20+0 records out20971520 bytes (21 MB) copied, 4.18921 s, 5.0 MB/s[zhongq@localhost ~]$ exit[root@localhost zhongq]# xfs_quota xfs_quota> helpdf [-bir] [-hn] [-f file] -- show free and used counts for blocks and inodeshelp [command] -- help for one or all commandsprint -- list known mount points and projectsquit -- exit the programquota [-bir] [-gpu] [-hnNv] [-f file] [id|name]... -- show usage and limitsUse 'help commandname' for extended help.xfs_quota> printFilesystem          Pathname/                   /dev/mapper/centos-root/boot               /dev/sda1/var/lib/docker     /dev/mapper/centos-root/xfsdata            /dev/mapper/xfsgroup00-xfsdata (uquota, gquota)xfs_quota> quota -u zhongqDisk quotas for User zhongq (1000)Filesystem                        Blocks      Quota      Limit  Warn/Time      Mounted on/dev/mapper/xfsgroup00-xfsdata    122880     102400     122880   00  [6 days]   /xfsdata

###############################################################################先使用命令lvextend將LV擴展為1.5G(初始容量是1G)，然后使用命令xfs_growfs來對xfs文件系統擴容（這里以block計數）

[root@localhost zhongq]# lvextend -L 1.5G /dev/xfsgroup00/xfsdata   Extending logical volume xfsdata to 1.50 GiB  Logical volume xfsdata successfully resized  [root@localhost zhongq]# xfs_growfs /dev/xfsgroup00/xfsdata -D 393216meta-data=/dev/mapper/xfsgroup00-xfsdata isize=256    agcount=4, agsize=65536 blks         =                       sectsz=512   attr=2, projid32bit=1         =                       crc=0data     =                       bsize=4096   blocks=262144, imaxpct=25         =                       sunit=0      swidth=0 blksnaming   =version 2              bsize=4096   ascii-ci=0 ftype=0log      =internal               bsize=4096   blocks=2560, version=2         =                       sectsz=512   sunit=0 blks, lazy-count=1realtime =none                   extsz=4096   blocks=0, rtextents=0data blocks changed from 262144 to 393216  [root@localhost zhongq]# df -h|grep xfsdata/dev/mapper/xfsgroup00-xfsdata  1.5G  153M  1.4G  10% /xfsdata