linux disk management knowledge and management of LVM Logical Volume Detailed
Foreword
Subsequently the article article ( https://blog.51cto.com/14557673/2447274) extend as follows :
- What is LVM? Why LVM?
- How to carry out specific LVM Logical Volume Management?
- What are disk quotas? Why do you need disk quotas?
- What conditions disk quotas in Linux is it?
- How specific disk quotas?
Here to explain each of the above issues, in-depth examples operate with you in-depth understanding of linux disk management LVM Logical Volume Management.
A, LVM Overview
1. What is LVM? Why LVM?
Many Linux users face such difficulties when installing the operating system: how to accurately assess and distribution capacity of each hard disk partition, if the original assessment is not accurate, once the system partition may have enough backup, delete data, or even forced re-zoning and reinstall the operating system to meet the needs of the application system. The LVM technology to achieve the needs of users of dynamic allocation of disk management.
LVM - Logical Volume Manger, logical volume management, Linux system is a logical disk partition management mechanism, which is built on the hard disk and partition, a logical layer below the file system, the file system at the time of the establishment a lower shielding disk partition layout, dynamic adjustment disk capacity while maintaining the existing data unchanged, thereby increasing the flexibility of disk management.
Note: / boot partition for storing boot files, it can not be based LVM created! ! !
The basic concept 2.LVM mechanism
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PV (physical volume)
Physical volume (physical volume), the storage device is substantially LVM mechanism, generally corresponding to a normal hard disk or the entire partition. When the head is created to create a hard disk partition or reserved blocks, used for recording attributes of the LVM, and the default size of the storage space is divided into a basic unit of 4MB (PE), a plurality of physical volumes configured PE
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VG (volume group)
A plurality of physical volumes configured volume group
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LV (Logical Volume)
Built on top of volume groups, and physical volumes are not directly related.
Schematic three as follows:
3.LVM key management command
| Features | Physical Volume Management | Volume Group Management | Logical Volume Management |
|---|---|---|---|
| scan scan | pvscan | vgscan | lvscan |
| create build | pvcreate | vgcreate | lvcreate |
| display display | pvdisplay | vgdisplay | lvdisplay |
| remove delete | pvremove | vgremove | lvremove |
| extend extension | —— | vgextend | lvextend |
| reduce reduce (some formats may not be supported) | —— | vgreduce | lvreduce |
The main table lists the specific logical volume management operation command, the actual operation on the following table demonstrates common commands.
Second, the process of practical operation LVM Logical Volume Manager (available now do)
4. How specific were LVM Logical Volume Management ?
Experimental environment: on VMware15 Centos7 version of the virtual machine operating environment
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Add the disk and restart the virtual machine, according to their specific needs and a few hardware restrictions
I added three specific steps can refer to: https://blog.51cto.com/14557673/2447274
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Check whether to add disk case is successful, the success of the operation to partition (which needs to be as the partition type ID tag number instead 8e, 8e expressed support for a LVM partition)
[root@lokott ~]# uname -a //显示Centos7的内核版本 Linux lokott 3.10.0-693.el7.x86_64 #1 SMP Tue Aug 22 21:09:27 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux [root@lokott ~]# fdisk -l 磁盘 /dev/sda：42.9 GB, 42949672960 字节，83886080 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：0x000a0791 设备 Boot Start End Blocks Id System /dev/sda1 * 2048 12584959 6291456 83 Linux /dev/sda2 12584960 54527999 20971520 83 Linux /dev/sda3 54528000 62916607 4194304 82 Linux swap / Solaris /dev/sda4 62916608 83886079 10484736 5 Extended /dev/sda5 62918656 83886079 10483712 83 Linux 磁盘 /dev/sdb：21.5 GB, 21474836480 字节，41943040 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 /dev/sdc：21.5 GB, 21474836480 字节，41943040 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 /dev/sdd：21.5 GB, 21474836480 字节，41943040 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Zoning as follows:
[root@lokott ~]# fdisk /dev/sdb //完成sdb和sdc的分区和分区类型设置 欢迎使用 fdisk (util-linux 2.23.2)。 ..... //中间交互过程省略，具体信息查看上述链接文章 命令(输入 m 获取帮助)：p 磁盘 /dev/sdb：21.5 GB, 21474836480 字节，41943040 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：0x5e2f4ad3 设备 Boot Start End Blocks Id System /dev/sdb1 2048 20973567 10485760 8e Linux LVM /dev/sdb2 20973568 31459327 5242880 83 Linux 命令(输入 m 获取帮助)：w [root@lokott ~]# fdisk /dev/sdc 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)：p 磁盘 /dev/sdc：21.5 GB, 21474836480 字节，41943040 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：0xfd710363 设备 Boot Start End Blocks Id System /dev/sdc1 2048 10487807 5242880 83 Linux /dev/sdc2 10487808 31459327 10485760 8e Linux LVMNow to the sdb1 and sdc2 as a logical partition, use fdisk -l to view information
[root@lokott ~]# fdisk -l /dev/sd[b-c] //简化操作 磁盘 /dev/sdb：21.5 GB, 21474836480 字节，41943040 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：0x5e2f4ad3 设备 Boot Start End Blocks Id System /dev/sdb1 2048 20973567 10485760 8e Linux LVM /dev/sdb2 20973568 31459327 5242880 83 Linux 磁盘 /dev/sdc：21.5 GB, 21474836480 字节，41943040 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：0xfd710363 设备 Boot Start End Blocks Id System /dev/sdc1 2048 10487807 5242880 83 Linux /dev/sdc2 10487808 31459327 10485760 8e Linux LVM [root@lokott ~]# -
After completion of partitioning, the desired operation using the command pvcreate partition to physical volume
[root@lokott ~]# pvscan //查看系统所有的物理卷，结果是没有 No matching physical volumes found [root@lokott ~]# pvcreate /dev/sdb1 /dev/sdc2 //转换分区为物理卷 Physical volume "/dev/sdb1" successfully created. Physical volume "/dev/sdc2" successfully created. [root@lokott ~]# pvdisplay //查看物理卷详细信息 "/dev/sdc2" is a new physical volume of "10.00 GiB" --- NEW Physical volume --- PV Name /dev/sdc2 VG Name PV Size 10.00 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID AzPaEA-X9Um-HPQQ-zdOg-mzVf-wXvh-QWEEXt "/dev/sdb1" is a new physical volume of "10.00 GiB" --- NEW Physical volume --- PV Name /dev/sdb1 VG Name PV Size 10.00 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID 5fh3Yx-Bwlm-ym7b-Qg0P-3HRb-iKRi-lwQyG9 -
Use vgcreate command to one or more physical volumes Volume Group
[root@lokott ~]# vgscan Reading volume groups from cache. [root@lokott ~]# vgcreate vgroup /dev/sdb1 /dev/sdc2 //vgroup是所建卷组的名字 Volume group "vgroup" successfully created [root@lokott ~]# vgdisplay --- Volume group --- VG Name vgroup System ID Format lvm2 Metadata Areas 2 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 2 Act PV 2 VG Size 19.99 GiB PE Size 4.00 MiB Total PE 5118 Alloc PE / Size 0 / 0 Free PE / Size 5118 / 19.99 GiB VG UUID K2s77S-fAfb-C5V2-P7ci-m4eo-DdNh-nanIW4 -
Dividing the lvcreate command from the user specified volume group to create the logical volume space.
[root@lokott ~]# lvscan //查看系统已建逻辑卷信息 [root@lokott ~]# lvcreate -L 10G -n vgroup1 vgroup //从卷组分割空间创建逻辑卷 Logical volume "vgroup1" created. [root@lokott ~]# ls /dev/vgroup/vgroup1 //显示逻辑卷vgroup1的链接文件 /dev/vgroup/vgroup1 [root@lokott ~]# ls /dev/mapper/vgroup-vgroup1 //显示逻辑卷vgroup1的设备文件 /dev/mapper/vgroup-vgroup1 [root@lokott ~]# lvdisplay //显示逻辑卷详细信息 --- Logical volume --- LV Path /dev/vgroup/vgroup1 LV Name vgroup1 VG Name vgroup LV UUID ucTRFz-DK1l-fVgf-Gvzr-562n-nkYS-kuRACZ LV Write Access read/write LV Creation host, time lokott, 2019-11-02 14:27:41 +0800 LV Status available # open 0 LV Size 10.00 GiB Current LE 2560 Segments 2 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:0 -
Logical volume is formatted, and create a mount point (mkdir) to mount, using the df command to view it
[root@lokott ~]# mkfs.xfs /dev/vgroup/vgroup1 meta-data=/dev/vgroup/vgroup1 isize=512 agcount=4, agsize=655360 blks = sectsz=512 attr=2, projid32bit=1 = crc=1 finobt=0, sparse=0 data = bsize=4096 blocks=2621440, 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 [root@lokott ~]# mkdir /mail [root@lokott ~]# mount /dev/vgroup/vgroup1 /mail/ [root@lokott ~]# df -hT 文件系统 类型 容量 已用 可用 已用% 挂载点 /dev/sda2 xfs 20G 4.4G 16G 22% / devtmpfs devtmpfs 474M 0 474M 0% /dev tmpfs tmpfs 489M 0 489M 0% /dev/shm tmpfs tmpfs 489M 7.2M 482M 2% /run tmpfs tmpfs 489M 0 489M 0% /sys/fs/cgroup /dev/sda5 xfs 10G 37M 10G 1% /home /dev/sda1 xfs 6.0G 158M 5.9G 3% /boot tmpfs tmpfs 98M 4.0K 98M 1% /run/user/42 tmpfs tmpfs 98M 24K 98M 1% /run/user/0 /dev/sr0 iso9660 4.3G 4.3G 0 100% /run/media/root/CentOS 7 x86_64 /dev/mapper/vgroup-vgroup1 xfs 10G 33M 10G 1% /mail - Use lvextend command logical capacity expansion, then use resize2fs command to update the file system size recognized by the system
[root@lokott ~]# lvextend -L +5G /dev/vgroup/vgroup1 //下面的信息表示成功扩展（前提是卷组中有空余空间）
Size of logical volume vgroup/vgroup1 changed from 10.00 GiB (2560 extents) to 15.00 GiB (3840 extents).
Logical volume vgroup/vgroup1 successfully resized.
[root@lokott ~]# df -hT //查看是没有显示出来需要更新让系统识别文件系统
文件系统 类型 容量 已用 可用 已用% 挂载点
/dev/sda2 xfs 20G 4.4G 16G 22% /
devtmpfs devtmpfs 474M 0 474M 0% /dev
tmpfs tmpfs 489M 0 489M 0% /dev/shm
tmpfs tmpfs 489M 7.2M 482M 2% /run
tmpfs tmpfs 489M 0 489M 0% /sys/fs/cgroup
/dev/sda5 xfs 10G 37M 10G 1% /home
/dev/sda1 xfs 6.0G 158M 5.9G 3% /boot
tmpfs tmpfs 98M 4.0K 98M 1% /run/user/42
tmpfs tmpfs 98M 24K 98M 1% /run/user/0
/dev/sr0 iso9660 4.3G 4.3G 0 100% /run/media/root/CentOS 7 x86_64
/dev/mapper/vgroup-vgroup1 xfs 10G 33M 10G 1% /mail
[root@lokott ~]# xfs_growfs /dev/vgroup/vgroup1 //xfs的使用xfs_growfs命令，ext4用resize2fs命令
meta-data=/dev/mapper/vgroup-vgroup1 isize=512 agcount=4, agsize=655360 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=2621440, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 2621440 to 3932160
[root@lokott ~]# df -hT | grep /dev/mapper/vgroup-vgroup1 //更新后可以查看到扩展到15G
/dev/mapper/vgroup-vgroup1 xfs 15G 33M 15G 1% /mail
[root@lokott ~]#
5. Experimental Summary (1)
Above is the whole process of LVM logical volume management operation, you can do what I do! Always operating logical partition when the partition note, and later requires updating command corresponding commands based on the file system type (ext4 - resize2fs, xfs - xfs_growfs)
Third, disk quotas
6. What are disk quotas? Why do you need disk quotas?
Disk quotas, by definition, is to limit the use of disk resources, disk quota system to control the user can use the disk resources (or limit). In Linux, you can use disk quotas to user space, number of files (in fact, is the number of the inode, the number of documents to limit the result of the inode) limit. If you exceed this range, the user can not continue to write data to the disk in.
For the average person, it may not be particularly good understanding of this section to explain that we give an example to illustrate:
Suppose a basket of peaches, a total of 50, the average allocation to 10 monkeys, each monkey can then be assigned to five peaches, first of all is to limit the number of peaches and peach total number can be assigned to each monkey, which is disk quota, but not necessarily the average allocation in the system, which need to be this quota allocation, some monkeys assigned to multi-point, then it means that some of the monkeys will be assigned will be less, but the total number will not change. For linux systems, it means that a single disk actual resource space is limited, so it is particularly important for the rational allocation of disk.
Therefore, the reason is that the disk quota disk space resources are limited, and its purpose can be understood as rational planning, to avoid waste of resources.
7. What are the conditions that disk quotas in Linux is it?
- First you need Linux kernel support
- Installation and quota xfsprogs
Features 8.Linux disk quota
- Range: for a specified file system (partition)
- Restrictions target: user accounts, group accounts
- Limit Type: disk capacity, the number of files
- Restriction method: soft limit, hard limit
Where the soft limit <= hard limit, soft limit or does not make sense, but the soft limit is to play really play the role of control methods
According following types and methods
- Capacity soft: bsoft
- Capacity Hard: bhard
- Number of soft: isoft
- Number of Hard: ihard
The following specific experiments give a specific process operation and demonstration of how to perform disk quota.
Fourth, disk quota specific steps experiments (experiments may then be operated above)
9. How specific disk quotas?
Specific procedure is as follows:
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First need to see if these two conditions are met
[root@lokott ~]# rpm -q xfsprogs //用rpm -q 进行查看上述两个条件的软件包是否在 xfsprogs-4.5.0-12.el7.x86_64 [root@lokott ~]# rpm -q quota quota-4.01-14.el7.x86_64 -
Condition is satisfied, then operation of the above experiment, to unmount (umount / mail)
[root@lokott ~]# umount /mail/ [root@lokott ~]# df -hT 文件系统 类型 容量 已用 可用 已用% 挂载点 /dev/sda2 xfs 20G 4.4G 16G 22% / devtmpfs devtmpfs 474M 0 474M 0% /dev tmpfs tmpfs 489M 0 489M 0% /dev/shm tmpfs tmpfs 489M 7.2M 482M 2% /run tmpfs tmpfs 489M 0 489M 0% /sys/fs/cgroup /dev/sda5 xfs 10G 37M 10G 1% /home /dev/sda1 xfs 6.0G 158M 5.9G 3% /boot tmpfs tmpfs 98M 4.0K 98M 1% /run/user/42 tmpfs tmpfs 98M 24K 98M 1% /run/user/0 /dev/sr0 iso9660 4.3G 4.3G 0 100% /run/media/root/CentOS 7 x86_64 -
Add usrquota and grpquota parameters unmounted functions to support the quota mount the file system
[root@lokott ~]# mount -o usrquota,grpquota /dev/vgroup/vgroup1 /mail/ [root@lokott ~]# mount | tail -1 //mount 命令结合“|”查看尾部一行的信息也可以使用下面的grep命令 /dev/mapper/vgroup-vgroup1 on /mail type xfs (rw,relatime,seclabel,attr2,inode64,usrquota,grpquota) [root@lokott ~]# mount | grep /dev/mapper/vgroup-vgroup1 /dev/mapper/vgroup-vgroup1 on /mail type xfs (rw,relatime,seclabel,attr2,inode64,usrquota,grpquota) -
Edit user and group account quota settings (here need to have a non-root user, you can view using the tail command / etc / passwd information, if no other user using useradd to create a user, description is given during the presentation)
[root@lokott ~]# tail -3 /etc/passwd //查看，我这里是由一个lokott的用户的，为了演示下面创建一个lisi postfix:x:89:89::/var/spool/postfix:/sbin/nologin tcpdump:x:72:72::/:/sbin/nologin lokott:x:1000:1000:lokott:/home/lokott:/bin/bash [root@lokott ~]# useradd lisi //创建新的用户账号和密码 [root@lokott ~]# passwd lisi 更改用户 lisi 的密码 。 新的 密码： 无效的密码： 密码少于 8 个字符 重新输入新的 密码： passwd：所有的身份验证令牌已经成功更新。 [root@lokott ~]# tail -3 /etc/passwd tcpdump:x:72:72::/:/sbin/nologin lokott:x:1000:1000:lokott:/home/lokott:/bin/bash lisi:x:1001:1001::/home/lisi:/bin/bash [root@lokott ~]# xfs_quota -x -c 'limit -u bsoft=1G bhard=2G isoft=20 ihard=50 lisi' /mail/Here for a detailed explanation of the bottom command, this command is a command truly edit user quota settings of the operation, which is xfs_quota commands, options -x represent the expert mode, -c indicates a command (command, in fact, single quotes content, similar to a database CRUD operations, limit represents the limit, -u representation of the user, the latter is to limit the size of the quota, then the user name, and finally do not forget to mount point !!!)
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Create a file permissions to view disk quota usage and verify disk quota feature, first mount privileges points to 777 in the root, otherwise it will be enough to switch users
[root@lokott ~]# xfs_quota -c 'quota -uv lisi' /mail/ //查看磁盘容量限制 Disk quotas for User lisi (1001) Filesystem Blocks Quota Limit Warn/Time Mounted on /dev/mapper/vgroup-vgroup1 0 1048576 2097152 00 [--------] /mail [root@lokott ~]# xfs_quota -c 'quota -iuv lisi' /mail/ //查看文件数量限制 Disk quotas for User lisi (1001) Filesystem Files Quota Limit Warn/Time Mounted on /dev/mapper/vgroup-vgroup1 0 20 50 00 [--------] /mail [root@lokott ~]# xfs_quota -x -c 'report -a' /mail/ //查看配额的所有信息 User quota on /mail (/dev/mapper/vgroup-vgroup1) Blocks User ID Used Soft Hard Warn/Grace ---------- -------------------------------------------------- root 0 0 0 00 [--------] lisi 0 1048576 2097152 00 [--------] Group quota on /mail (/dev/mapper/vgroup-vgroup1) Blocks Group ID Used Soft Hard Warn/Grace ---------- -------------------------------------------------- root 0 0 0 00 [--------] [root@lokott ~]# chmod 777 /mail/ [root@lokott ~]# su - lisi //切换用户 上一次登录：六 11月 2 16:15:17 CST 2019pts/0 上 [lisi@lokott ~]$ cd /mail/ //进入挂载点目录创建文件方式来验证（方法一） [lisi@lokott mail]$ ls [lisi@lokott mail]$ touch {1..20}.txt [lisi@lokott mail]$ ls 10.txt 12.txt 14.txt 16.txt 18.txt 1.txt 2.txt 4.txt 6.txt 8.txt 11.txt 13.txt 15.txt 17.txt 19.txt 20.txt 3.txt 5.txt 7.txt 9.txt [lisi@lokott mail]$ touch {20..60}.txt //上面查看的数量限制是50，现在超过50了 touch: 无法创建"51.txt": 超出磁盘限额 touch: 无法创建"52.txt": 超出磁盘限额 touch: 无法创建"53.txt": 超出磁盘限额 touch: 无法创建"54.txt": 超出磁盘限额 touch: 无法创建"55.txt": 超出磁盘限额 touch: 无法创建"56.txt": 超出磁盘限额 touch: 无法创建"57.txt": 超出磁盘限额 touch: 无法创建"58.txt": 超出磁盘限额 touch: 无法创建"59.txt": 超出磁盘限额 touch: 无法创建"60.txt": 超出磁盘限额 [lisi@lokott mail]$ ls | wc -l //表示成功创建了30个 50 [lisi@lokott mail]$ su //切换到root下看一下数量限制的变化，其中warn/time变为6days 密码： [root@lokott mail]# cd [root@lokott ~]# xfs_quota -c 'quota -iuv lisi' /mail/ //查看数量配额限制功能 Disk quotas for User lisi (1001) Filesystem Files Quota Limit Warn/Time Mounted on /dev/mapper/vgroup-vgroup1 50 20 50 00 [6 days] /mail10. Experimental summary (2):
After the disk quota operations, its limits are very strict, above we verify the effect of the number of disk quota restrictions by the method of creating the file where the warning time indicates the start to six days from tomorrow, more than due to the soft limit 40 limit the number of nodes files, 10 files created later will be deleted!
Below and to verify the capacity limit by the quota dd command:
[root@lokott ~]# su - lisi //首先切换到lisi用户上cd到挂载点目录删除原来的文件 上一次登录：六 11月 2 16:46:28 CST 2019pts/0 上 [lisi@lokott ~]$ cd /mail/ [lisi@lokott mail]$ ls 10.txt 14.txt 18.txt 21.txt 25.txt 29.txt 32.txt 36.txt 3.txt 43.txt 47.txt 50.txt 8.txt 11.txt 15.txt 19.txt 22.txt 26.txt 2.txt 33.txt 37.txt 40.txt 44.txt 48.txt 5.txt 9.txt 12.txt 16.txt 1.txt 23.txt 27.txt 30.txt 34.txt 38.txt 41.txt 45.txt 49.txt 6.txt 13.txt 17.txt 20.txt 24.txt 28.txt 31.txt 35.txt 39.txt 42.txt 46.txt 4.txt 7.txt [lisi@lokott mail]$ rm *.txt -f //删除所有文件然后使用dd命令操作，软限制1G 硬限制2G [lisi@lokott mail]$ cd [lisi@lokott ~]$ dd if=/dev/zero of=/mail/demo01.txt bs=50M count=10 //第一次没问题 记录了10+0 的读入 记录了10+0 的写出 524288000字节(524 MB)已复制，0.647092 秒，810 MB/秒 [lisi@lokott ~]$ dd if=/dev/zero of=/mail/demo02.txt bs=50M count=20 //第二次没问题 记录了20+0 的读入 记录了20+0 的写出 1048576000字节(1.0 GB)已复制，0.685654 秒，1.5 GB/秒 [lisi@lokott ~]$ dd if=/dev/zero of=/mail/demo03.txt bs=50M count=20 //第三次失败了 dd: 写入"/mail/demo03.txt" 出错: 超出磁盘限额 记录了11+0 的读入 记录了10+0 的写出 574619648字节(575 MB)已复制，0.357243 秒，1.6 GB/秒 [lisi@lokott ~]$ du -sh /mail/ //统计目录空间大小使用情况 2.0G /mail/ [lisi@lokott ~]$ ls -lh /mail/ //查看详细信息 总用量 2.0G -rw-rw-r--. 1 lisi lisi 500M 11月 2 17:08 demo01.txt -rw-rw-r--. 1 lisi lisi 1000M 11月 2 17:09 demo02.txt -rw-rw-r--. 1 lisi lisi 548M 11月 2 17:10 demo03.txt [lisi@lokott ~]$ su 密码： [root@lokott lisi]# cd [root@lokott ~]# xfs_quota -c 'quota -uv lisi' /mail/ //查看容量配额限制功能 Disk quotas for User lisi (1001) Filesystem Blocks Quota Limit Warn/Time Mounted on /dev/mapper/vgroup-vgroup1 2097152 1048576 2097152 00 [6 days] /mail11. Experimental summary (3)
By dd command (dd command is a copy of a specified size block of a file, and the specified conversion simultaneous copies) to verify the function test to verify disk quota capacity constraints, seen This is similar to a method of verifying the results of the experiment During operation note the following points:
You need to switch user authentication and content updates mount point (if the second method without first deleting the original file, is not the experiment)
V. Summary
To do this paper leads to several problems begins to illustrate the concept and management of logical volumes LVM, the concept of disk quotas, why should the quotas and how to operate specific quotas verification experiment, the point to note in the above experiment Summary and the principles set forth in the cause. Experiments in great detail, I can do what I do! ! Thank you for reading!