KVM (11) Libguestfs Tools

Ibguestfs is a set of C-language APIs under Linux that are used to access the disk image files of a virtual machine. Its project homepage is http://libguestfs.org/, which contains tools such as Virt-cat, VIRT-DF, Virt-ls, virt-copy-in, Virt-copy-out, Virt-edit, Guestfs, Guestmount, Virt-list-filesystems, virt-list-partitions and other tools, specific usage can also be see the official website. The tool can directly view the content within the guest host without starting the KVM guest host, or it can write files and copy files directly to the IMG image, and it can also support mount operations like Mount.

First, the installation of Libguestfs-tools

[Email protected] ~]# yum-y install Libguestfs-tools

List all command tools

[[email protected] ~]# virt-virt-alignment-scan    virt-df                 virt-inspector          virt-make-fs            virt-sysprep           virt-whatvirt-cat                virt-edit               virt-inspector2         virt-manager            virt-tar                virt-win-regvirt-clone              Virt-filesystems     &nBsp; virt-install           virt-pki-validate       virt-tar-in             virt-xml-validatevirt-convert            virt-format            virt-list-filesystems   virt-rescue            virt-tar-out            virt-copy-in            virt-host-validate     virt-list-partitions    virt-resize            virt-top                virt-copy-out        &nbsP;  virt-image             virt-ls                 virt-sparsify           virt-viewer

Virt-ls: You can list files or directories in a directory in a virtual machine

[Email protected] kvm]# virt-ls-d Vm1/etc/.pwd.lockconsolekitdir_colorsdir_colors.256colordir_colors.lightbgcolor

Virt-top: Similar to the top command, except that the process was replaced with a virtual machine

[Email protected] kvm]# Virt-top

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This is all my VMS.

Virt-cat: You can view the contents of a file in a virtual machine

[Email protected] kvm]# virt-cat-d vm1/etc/passwd

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Virt-edit: You can edit files in a VM

[Email protected] kvm]# virt-edit-d vm1/root/testfile

I'll enter a few "dddddddd" strings here.

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Virt-copy-in: Copy files to the virtual machine

[Email protected] ~]# virt-copy-in-d vm1 a/opt/

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you can also operate directly on a virtual machine disk file by simply -d domnameReplace -a path_of_disk_file（虚拟机的磁盘文件），上面的操作都可以
Virt-copy-out: You can copy the files from the virtual machine to the local host

[Email protected] ~]# virt-copy-out-d vm1/opt/a/etc/passwd.

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Copy-out the two files vm1 the virtual machine

Virt-what

Virt-what can be used to detect whether the current system is not a virtual machine, if it is not a virtual machine, the execution of Virt-what will not have any output, if it is a virtual machine, it will print a series of virtual machine "facts" (such as KVM, Vmwar, Xen, etc.)

[Email protected] ~]# Virt-what

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Virt-host-validate

This command can be used to detect if the machine is properly configured to run virtualization, and if no parameters are added, it will check all the virtualization drivers it knows, optionally adding qemu or lxc restricting

[Email protected] ~]# virt-host-validate

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VIRT-DF: will be executed in the virtual machine dfResult output of the command

[Email protected] ~]# virt-df-d VM1

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Virt-alignment-scan

The old operating system is installed with an unaligned partition, which can cause some unnecessary I/O, the role of this command is to check whether the problem is not aligned, if present, just warning (warns) you, this tool will not help you solve this problem

[Email protected] ~]# Virt-alignment-scan

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Virt-inspector2

This command can display the operating system version and some other information of the virtual machine, contains very much information and is very simple to use

[Email protected] ~]# virt-inspector2-d VM1

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Virt-resize in front has been tested demo

• Virt-resize can adjust the size of the virtual machine disk, adjust or delete any partition

• Virt-resize can not adjust the disk in place, should not make disk adjustment to the running virtual machine, in order to ensure consistency, the tuning needs to shut down the virtual machine first

• The process of virt-resize adjustment is very slow, it takes about 10 minutes to scale from a 35G disk

• Virt-resize adjustment is only related to the size of the start disk, from 35G to 40G and the time it takes to expand to 135G.

• If you use the QCOW2 disk format, personal advice to first turn to raw, adjust and then go back, because directly to qcow2 adjustment, compare 35G qcow2 disk image file may only 1G size (LS view), through the virt-resize adjustment will become 35G size ( LS view) (may also be my method is not correct), first turn to raw to adjust the size and then go back to avoid this problem

Virt-install

When installing a virtual machine, it is common

Such as:

[Email protected] ~]# virt-install--name=vm2--ram,--vcpus=1--disk path=/image/vm2.img,size=7,bus=virtio-- Accelerate--cdrom=/iso/rhel6.5/rhel-server-6.5-x86_64-dvd.iso--vnc--vncport=5910--vnclisten=0.0.0.0--network Bridge=br0,model=virtio--noautoconsole

viewing partition information

Virt-filesystems//Virt-list-filesystems

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This article is from the "Big Wind" blog, please be sure to keep this source http://lansgg.blog.51cto.com/5675165/1691773

KVM (11) Libguestfs Tools