XFS是扩展性高、高性能的文件系统。也是rhel7/centos7的默认文件系统。XFS支持metadata journaling,这使其能从crash中更快速的恢复。它也支持在挂载和活动的状态下进行碎片整理和扩容。通过延迟分配，XFS 赢得了许多机会来优化写性能。可通过工具xfsdump和xfsrestore来备份和恢复xfs文件系统，xfsdump可使用dump级别来完成增量备份，还可通过size,subtree,inode flags来排除文件。也支持user、group、project配额。
下面将介绍如何创建xfs文件系统，，分配配额以及对其扩容:###############################################################################将/dev/sdb分区（2G），并启动LVM功能
[root@localhost zhongq]#parted /dev/sdbGNU 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) pModel: VMware, VMware Virtual S (scsi)Disk /dev/sdb: 2147MBSector size (logical/physical): 512B/512BPartition Table: gptDisk Flags: Number Start EndSize File system NameFlags 14194kB 2048MB 2044MBprimary lvm
###############################################################################创建PV
[root@localhost zhongq]# pvcreate /dev/sdb1 Physical volume “/dev/sdb1″ successfully created[root@localhost zhongq]# pvdisplay — Physical volume — PV Name/dev/sda2 VG Namecentos PV Size24.51 GiB / not usable 3.00 MiB Allocatableyes (but full) PE Size4.00 MiB Total PE6274 Free PE0 Allocated PE6274 PV UUID9hp8U7-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 NamePV Size1.90 GiB AllocatableNO PE Size0Total PE0 Free PE0 Allocated PE0 PV UUIDbu7yIH-1440-BPy1-APG2-FpvX-ejLS-2MIlA8
###############################################################################将/dev/sdb1分配到名为xfsgroup00的VG
[root@localhost zhongq]# vgcreate xfsgroup00 /dev/sdb1 Volume group “xfsgroup00” successfully created[root@localhost zhongq]# vgdisplay — Volume group — VG Namecentos System IDFormatlvm2 Metadata Areas1 Metadata Sequence No 3 VG Accessread/write VG Statusresizable MAX LV0 Cur LV2 Open LV2 Max PV0 Cur PV1 Act PV1 VG Size24.51 GiB PE Size4.00 MiB Total PE6274 Alloc PE / Size6274 / 24.51 GiB Free PE / Size0 / 0VG UUIDT3Ryyg-R0rn-2i5r-7L5o-AZKG-yFkh-CDzhKm— Volume group — VG Namexfsgroup00 System IDFormatlvm2 Metadata Areas1 Metadata Sequence No 1 VG Accessread/write VG Statusresizable MAX LV0 Cur LV0 Open LV0 Max PV0 Cur PV1 Act PV1 VG Size1.90 GiB PE Size4.00 MiB Total PE487 Alloc PE / Size0 / 0Free PE / Size487 / 1.90 GiB VG UUIDejuwcc-sVES-MWWB-3Mup-n1wB-Kd0g-u7jm0H
###############################################################################使用命令lvcreate来创建xfsgroup00组大小为1G的名为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 Nameswap VG Namecentos LV UUIDEnW3at-KlFG-XGaQ-DOoH-cGPP-8pSf-teSVbh LV Write Accessread/write LV Creation host, time localhost, 2014-08-18 20:15:25 +0800 LV Statusavailable # open2 LV Size2.03 GiB Current LE520 Segments1 Allocationinherit Read ahead sectorsauto – currently set to8192 Block device253:0— Logical volume — LV Path/dev/centos/root LV Nameroot VG Namecentos LV UUIDzmZGkv-Ln4W-B8AY-oDnD-BEk2-6VWL-L0cZOv LV Write Accessread/write LV Creation host, time localhost, 2014-08-18 20:15:26 +0800 LV Statusavailable # open1 LV Size22.48 GiB Current LE5754 Segments1 Allocationinherit Read ahead sectorsauto – currently set to8192 Block device253:1— Logical volume — LV Path/dev/xfsgroup00/xfsdata LV Namexfsdata VG Namexfsgroup00 LV UUIDO4yvoY-XGcD-0zPm-eilR-3JJP-updU-rRCSlJ LV Write Accessread/write LV Creation host, time localhost.localdomain, 2014-09-23 15:50:19 +0800 LV Statusavailable # open0 LV Size1.00 GiB Current LE256 Segments1 Allocationinherit Read ahead sectorsauto – currently set to8192 Block device253:3
###############################################################################格式化分区为xfs文件系统。注意：xfs被创建后，其size将无法缩小，但可以通过xfs_growfs来增大
[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=0swidth=0 blksnaming =version 2bsize=4096 ascii-ci=0 ftype=0log=internal logbsize=4096 blocks=2560, version=2=sectsz=512 sunit=0 blks, lazy-count=1realtime =noneextsz=4096 blocks=0, rtextents=0
###############################################################################挂载xfs系统分区到指定目录，并通过参数uquota,gquota开启文件系统配额。
这一次是一个告别，或者一个永远的告别，
