本篇内容：
一、Linux下的系统配额
二、Linux下RAID
一、系统磁盘配额
设置和检查文件系统上的磁盘配额，预防用户使用超出允许量的空间，还要预防整个文件系统被意外填满。
综述
在内核中执行
以文件系统为单位启用
对不同组或者用户的策略不同
根据块或者节点进行限制
软限制（soft limit）：软限制： 警告限制，可以被突破
硬限制（hard limit）：最大可用限制，不可突破；
配额大小：以K为单位，以文件个数为单位
初始化
分区挂载选项：usrquota、grpquota
初始化数据库：quotacheck
执行
开启或者取消配额：quotaon、quotaoff
直接编辑配额：edquota username
在shell中直接编辑：
setquota usename 4096 5120 40 50 /foo
定义原始标准用户
edquota -p user1 user2
报告
用户调查：quota
配额概述：repquota
其它工具：warnquota
创建一个分区并格式化，然后挂载至/home目录下，对此目录实现磁盘配额
1、创建一个10G的分区并且格式化为ext4系统
[[email protected] ~]# fdisk /dev/sdb [[email protected] ~]# lsblk /dev/sdb NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sdb 8:16 0 90G 0 disk └─sdb1 8:17 0 10G 0 part [[email protected] ~]# mkfs.ext4 /dev/sdb1
2、将/home目录下的文件移动到其他目录，然后将/dev/sdb1挂载至home目录下，再将数据复制回来。
[[email protected] ~]# mv /home/* /testdir/ [[email protected] ~]# ls /home/ [[email protected] ~]# [[email protected] ~]# mount /dev/sdb1 /home/ //将/dev/sdb1挂载至/home目录下 [[email protected] ~]# ls /home/ lost+found [[email protected] ~]# mv /testdir/* /home/ //将/home下原来的数据移动回来 [[email protected] ~]# ls /home/ lost+found xiaoshui
3、写入/etc/fstab，并且将挂载选项设为usrquota，grpquota，因为刚刚没有写挂载选项，需要卸载后重新挂载。
[[email protected] ~]# vi /etc/fstab # # /etc/fstab # Created by anaconda on Mon Jul 25 09:34:22 2016 # # 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 # /dev/mapper/vg0-root / ext4 defaults 1 1 UUID=7bbc50de-dfee-4e22-8cb6-04d8520b6422 /boot ext4 defaults 1 2 /dev/mapper/vg0-usr /usr ext4 defaults 1 2 /dev/mapper/vg0-var /var ext4 defaults 1 2 /dev/mapper/vg0-swap swap swap defaults 0 0 tmpfs /dev/shm tmpfs defaults 0 0 devpts /dev/pts devpts gid=5,mode=620 0 0 sysfs /sys sysfs defaults 0 0 proc /proc proc defaults 1 0 /dev/sdb1 /home ext4 usrquota,grpquota 0 0 [[email protected] ~]# umount /home/ [[email protected] ~]# mount -a
4、创建配额数据库
[[email protected] ~]# quotacheck -cug /home
5、启用数据库
[[email protected] ~]# quotaon -p /home //查看是否启用数据库 group quota on /home (/dev/sdb1) is off user quota on /home (/dev/sdb1) is off [[email protected] ~]# quotaon /home //启用数据库
6、配置配额项
[[email protected] ~]# edquota xiaoshui //soft为软限制，hard为硬限制 Disk quotas for user xiaoshui (uid 500): Filesystem blocks soft hard inodes soft hard /dev/sdb1 32 300000 500000 8 0 0
7、切换到xiaoshui用户，来测试是否上述设置是否生效
[[email protected] ~]# su - xiaoshui //切换用户只xiaoshui [[email protected] ~]$ pwd /home/xiaoshui [[email protected] ~]$ dd if=/dev/zero of=file1 bs=1M count=290 //先新建一个290MB的文件 290+0 records in 290+0 records out 304087040 bytes (304 MB) copied, 1.08561 s, 280 MB/s //创建成功，并没有报错 [[email protected] ~]$ dd if=/dev/zero of=file1 bs=1M count=300 //覆盖file1，创建一个300MB的文件 sdb1: warning, user block quota exceeded. //出现警告! 300+0 records in 300+0 records out 314572800 bytes (315 MB) copied, 0.951662 s, 331 MB/s [[email protected] ~]$ ll -h 查看文件，发现依然创建成功 total 300M -rw-rw-r-- 1 xiaoshui xiaoshui 300M Aug 26 08:16 file1 [[email protected] ~]$ dd if=/dev/zero of=file1 bs=1M count=500 //继续覆盖file1，创建一个500MB的文件 sdb1: warning, user block quota exceeded. sdb1: write failed, user block limit reached. //出现警告，提示用户的block到了限制 dd: writing `file1‘: Disk quota exceeded 489+0 records in 488+0 records out 511967232 bytes (512 MB) copied, 2.344 s, 218 MB/s [[email protected] ~]$ ll -h //查看文件，发现并没有500MB的文件，系统自动dd过程停止了 total 489M -rw-rw-r-- 1 xiaoshui xiaoshui 489M Aug 26 08:19 file1
8、报告配额状态
[[email protected] ~]# quota xiaoshui //blocks显示了用户现在的文件block数，已经超过了limit Disk quotas for user xiaoshui (uid 500): Filesystem blocks quota limit grace files quota limit grace /dev/sdb1 500004* 300000 500000 6days 10 0 0
RAID
一、什么是RAID
RAID:Redundant Arrays of Inexpensive（Independent）Disks，多个磁盘合成一个“阵列”来提供更好的性能、冗余，或者两者都提供
优点：
提高IO能力：
磁盘并行读写
提高耐用性；
磁盘冗余来实现
二、RAID级别
RAID-0：条带卷，strip
读、写性能提升；
可用空间：N*min(S1,S2,...)
无容错能力
最少磁盘数：2, 2
RAID-1: 镜像卷，mirror
读性能提升、写性能略有下降；
可用空间：1*min(S1,S2,...)
有冗余能力
最少磁盘数：2, 2N
RAID-2
..
RAID-5
读、写性能提升
可用空间：(N-1)*min(S1,S2,...)
有容错能力：有校验位，允许最多1块磁盘损坏
最少磁盘数：3, 3+
RAID-6
读、写性能提升
可用空间：(N-2)*min(S1,S2,...)
有容错能力：允许最多2块磁盘损坏
最少磁盘数：4, 4+
RAID-10
读、写性能提升
可用空间：N*min(S1,S2,...)/2
有容错能力：每组镜像最多只能坏一块
最少磁盘数：4, 4+
RAID-01
先RAID0,在RAID1
软件实现RAID 5
1、准备磁盘分区
[[email protected] ~]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 80G 0 disk ├─sda1 8:1 0 488M 0 part /boot ├─sda2 8:2 0 40G 0 part / ├─sda3 8:3 0 20G 0 part /usr ├─sda4 8:4 0 512B 0 part ├─sda5 8:5 0 2G 0 part [SWAP] └─sda6 8:6 0 1M 0 part sdb 8:16 0 80G 0 disk └─sdb1 8:17 0 1G 0 part sdc 8:32 0 20G 0 disk sdd 8:48 0 20G 0 disk ├─sdd1 8:49 0 100M 0 part ├─sdd2 8:50 0 100M 0 part ├─sdd3 8:51 0 100M 0 part ├─sdd4 8:52 0 1K 0 part └─sdd5 8:53 0 99M 0 part sde 8:64 0 20G 0 disk └─sde1 8:65 0 100M 0 part sdf 8:80 0 20G 0 disk sr0 11:0 1 7.2G 0 rom
准备四块磁盘分区，分区类型设为RAID类型(fd),我这里为/dev/sdd{1,2,3}，/dev/sde1
2、创建RAID 5
[[email protected] ~]# mdadm -C /dev/md0 -a yes -l 5 -n 3 -x1 /dev/sd{d{1,2,3},e1}
mdadm: /dev/sdd1 appears to be part of a raid array:
level=raid5 devices=4 ctime=Mon Aug 29 19:43:21 2016
mdadm: /dev/sdd2 appears to be part of a raid array:
level=raid0 devices=0 ctime=Thu Jan 1 08:00:00 1970
mdadm: partition table exists on /dev/sdd2 but will be lost or
meaningless after creating array
Continue creating array? yes
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.
[[email protected] ~]# mdadm -D /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Thu Sep 1 14:39:53 2016
Raid Level : raid5
Array Size : 202752 (198.03 MiB 207.62 MB)
Used Dev Size : 101376 (99.02 MiB 103.81 MB)
Raid Devices : 3
Total Devices : 4
Persistence : Superblock is persistent
Update Time : Thu Sep 1 14:39:54 2016
State : clean
Active Devices : 3
Working Devices : 4
Failed Devices : 0
Spare Devices : 1
Layout : left-symmetric
Chunk Size : 512K
Name : localhost.localdomain:0 (local to host localhost.localdomain)
UUID : f4eaf910:514ae7ab:6dd6d28f:b6cfcc10
Events : 18
Number Major Minor RaidDevice State
0 8 49 0 active sync /dev/sdd1
1 8 50 1 active sync /dev/sdd2
4 8 51 2 active sync /dev/sdd3
3 8 65 - spare /dev/sde1
[[email protected] ~]#
3、格式化文件系统
[[email protected] ~]# mkfs.ext4 /dev/md0 mke2fs 1.42.9 (28-Dec-2013) Filesystem label= OS type: Linux Block size=1024 (log=0) Fragment size=1024 (log=0) Stride=512 blocks, Stripe width=1024 blocks 50800 inodes, 202752 blocks 10137 blocks (5.00%) reserved for the super user First data block=1 Maximum filesystem blocks=33816576 25 block groups 8192 blocks per group, 8192 fragments per group 2032 inodes per group Superblock backups stored on blocks: 8193, 24577, 40961, 57345, 73729 Allocating group tables: done Writing inode tables: done Creating journal (4096 blocks): done Writing superblocks and filesystem accounting information: done
4、生成配置文件并启动RAID 5然后挂载
[[email protected] ~]# mdadm -Ds /dev/md0 > /etc/mdadm.conf [[email protected] ~]# mdadm -A /dev/md0 mdadm: /dev/md0 has been started with 3 drives and 1 spare. [[email protected] ~]# mount /dev/md0 /testdir/
5、测试
[[email protected] ~]# cd /testdir/ [[email protected] testdir]# ls lost+found [[email protected] testdir]# cp /etc/* . //向挂载目录拷贝文件 [[email protected] testdir]# mdadm -D /dev/md0 //查看RAID运行状态 /dev/md0: Version : 1.2 Creation Time : Thu Sep 1 14:39:53 2016 Raid Level : raid5 Array Size : 202752 (198.03 MiB 207.62 MB) Used Dev Size : 101376 (99.02 MiB 103.81 MB) Raid Devices : 3 Total Devices : 4 Persistence : Superblock is persistent Update Time : Thu Sep 1 14:47:58 2016 State : clean Active Devices : 3 Working Devices : 4 Failed Devices : 0 Spare Devices : 1 Layout : left-symmetric Chunk Size : 512K Name : localhost.localdomain:0 (local to host localhost.localdomain) UUID : f4eaf910:514ae7ab:6dd6d28f:b6cfcc10 Events : 18 Number Major Minor RaidDevice State //三个分区正常运行 0 8 49 0 active sync /dev/sdd1 1 8 50 1 active sync /dev/sdd2 4 8 51 2 active sync /dev/sdd3 3 8 65 - spare /dev/sde1 [[email protected] testdir]# mdadm /dev/md0 -f /dev/sdd1 //模拟/dev/sdd1损坏 mdadm: set /dev/sdd1 faulty in /dev/md0 [[email protected] testdir]# mdadm -D /dev/md0 //再次查看磁盘状态 /dev/md0: Version : 1.2 Creation Time : Thu Sep 1 14:39:53 2016 Raid Level : raid5 Array Size : 202752 (198.03 MiB 207.62 MB) Used Dev Size : 101376 (99.02 MiB 103.81 MB) Raid Devices : 3 Total Devices : 4 Persistence : Superblock is persistent Update Time : Thu Sep 1 14:51:01 2016 State : clean Active Devices : 3 Working Devices : 3 Failed Devices : 1 Spare Devices : 0 Layout : left-symmetric Chunk Size : 512K Name : localhost.localdomain:0 (local to host localhost.localdomain) UUID : f4eaf910:514ae7ab:6dd6d28f:b6cfcc10 Events : 37 Number Major Minor RaidDevice State 3 8 65 0 active sync /dev/sde1 1 8 50 1 active sync /dev/sdd2 4 8 51 2 active sync /dev/sdd3 0 8 49 - faulty /dev/sdd1 ///dev/sdd1已经标记为损坏，并且之前的/dev/sde1自动补上去了 [[email protected] testdir]# cat fstab //依然正常查看文件 # # /etc/fstab # Created by anaconda on Mon Jul 25 12:06:44 2016 # # 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=136f7cbb-d8f6-439b-aa73-3958bd33b05f / xfs defaults 0 0 UUID=bf3d4b2f-4629-4fd7-8d70-a21302111564 /boot xfs defaults 0 0 UUID=cbf33183-93bf-4b4f-81c0-ea6ae91cd4f6 /usr xfs defaults 0 0 UUID=5e11b173-f7e2-4994-95b9-55cc4c41f20b swap swap defaults 0 0 [[email protected] testdir]# mdadm /dev/md0 -r /dev/sdd1 //模拟拔出硬盘 [[email protected] testdir]# mdadm -D /dev/md0 ..............................省略........................ Number Major Minor RaidDevice State 3 8 65 0 active sync /dev/sde1 //已经找不到/dev/sdd1 1 8 50 1 active sync /dev/sdd2 4 8 51 2 active sync /dev/sdd3 [[email protected] testdir]# [[email protected] testdir]# mdadm /dev/md0 -a /dev/sdd1 //模拟增加硬盘 mdadm: added /dev/sdd1 [[email protected] testdir]# mdadm -D /dev/md0 //查看信息 ..............................省略........................ Number Major Minor RaidDevice State 3 8 65 0 active sync /dev/sde1 1 8 50 1 active sync /dev/sdd2 4 8 51 2 active sync /dev/sdd3 5 8 49 - spare /dev/sdd1 /// /dev/sdd1成功增加 [[email protected] testdir]# mdadm /dev/md0 -f /dev/sdd2 //因为RAI5 中有校验位，允许其中的一块磁盘损坏掉，通过校验位可以把原来的数据文件给推算出来 mdadm: set /dev/sdd2 faulty in /dev/md0 [[email protected] testdir]# mdadm -D /dev/md0 ..............................省略........................ Number Major Minor RaidDevice State 5 8 49 0 active sync /dev/sdd1 2 0 0 2 removed 4 8 51 2 active sync /dev/sdd3 1 8 50 - faulty /dev/sdd2 3 8 65 - faulty /dev/sde1 //这种情况下依然能查看数据文件，不过性能会下降，所以需要立即修复
时间： 2024-10-04 07:20:12