QEMU starts the virtual machine sheepdog

Preface

Sheepdog is a virtual machine Distributed file system designed specifically for QEMU, with a completely symmetric structure and no central node of the metadata service, thus eliminating the risk of a single point of failure. This article is based on the latest 0.7.0 release Test, which describes the installation configuration and use of sheepdog. Sheepdog back-end cluster management

Sheepdog backend Cluster Management is used to manage membership and message communication between nodes. There are currently four modes available, namely local driver (for stand-alone testing), Corosync (default), Zookeeper and Accord.

There are two types of models:

– Full symmetry (dependent on Corosync, running in Sheepdog's address space)

Cons: Small scale [<100]

Pros: No Configuration required

– Separate control cluster (dependent on accord* or Zookeeper, running in separate address space)

Cons: Need to configure control cluster

Advantages: Large scale [>1000]

The default Corosync mode is used for this test.

Preparation before installation:

Do some system setup first

echo "* Soft nofile 65533" >>/etc/security/limits. conf echo "* Hard Nofile 65533" >>/etc/security/limits. conf Yum install-y make Automake autoconf gcc nss-devel wget git glib2

Installing the Epel source

RPM-IVH http://dl. Fedoraproject. ORG/PUB/EPEL/6/x86_64/epel-release-6-8. Noarch. Rpm

Installing Sheepdog 1). Install Corosync

CENTOS6 comes with an old version, we need to install the new

Yum Remove Corosync corosynclib corosynclib-devel-y git clone git://GitHub. Com/corosync/corosync. git cd corosync git checkout-b flatiron origin/flatiron./Autogen. Sh./configure--ENABLE-NSS make install

2). Install Sheepdog

Cd/home2/install git clone git://GitHub. Com/collie/sheepdog. Git CD Sheepdog./Autogen. Sh./Configure make Install

configuring Corosync and Sheepdog

Cd/etc/corosync CP Corosync. Conf. Example Corosync. Conf

Edit corosync.conf Modify bindnetaddr into your network segment like 192.168.1.0

# Please read the corosync. Conf 5 manual page Compatibility:whitetank totem {version:2 Secauth:off threads:0 # Note, Fail_recv_const is only n eeded If you ' re # have problems with Corosync crashing under # Heavy sheepdog traffic. This crash are due to # delayed/resent/misordered multicast packets. # fail_recv_const:5000 Interface {ringnumber:0 bindnetaddr:192.168.1.0 mcastaddr:226.94.1.1 mcastport:5405}} L ogging {fileline:off to_stderr:no to_logfile:yes To_syslog:yes # The pathname of the log file logfile:/Var/log/ Cluster/corosync. Log Debug:off timestamp:on Logger_subsys {SUBSYS:AMF Debug:off}} AMF {mode:disabled}

Start the service

/Etc/init. D/corosync start # or start by command (/Var/lib/sheepdog is the data directory that sheepdog uses, you can change to other) # Sheep/var/lib/sheepdog

Sheepdog requires that the/var/lib/sheepdog directory is located in a partition that supports XATTR

Mount-o remount, user_xattr/

The above operations need to be performed on each sheepdog node

Format the sheepdog cluster and set up 3 replicas, just on one of the nodes to perform

Collie cluster Format--copies = 3

View node Status

Collie Node List

This sheepdog cluster has been configured to create Sheepdog disk images using qemu-img

Since the qemu1.2 version of CENTOS6 does not support sheepdog, a new version of QEMU is compiled here.

Installing a dependent Package

Yum Install Zlib-devel glib2-devel-y

Compiling QEMU

wget http://wiki. Qemu-project. org/download/qemu-1.5. 2. Tar. bz2 tar jxvf qemu-1.5. 2. Tar. BZ2 CD qemu-1.5. 2./configure make; Make install

Create Disk

/usr/local/bin/qemu-img create-f qcow2 sheepdog:myfirstdisk 10G

If the sheepdog is running on another machine, you need to specify the IP and port

/usr/local/bin/qemu-img create-f qcow2 sheepdog:192.168. 1.100:7000:myfirstdisk 10G

List the images in sheepdog

Collie VDI List

Convert an existing image into sheepdog

Qemu-img Convert./mysystem. Raw Sheepdog:mysystem start a virtual machine

qemu-system-x86_64--enable-kvm-m 1024-drive file = sheepdog:myfirstdisk, cache = writeback-vnc:15-cdrom/data/ Centos-6.4-i386-minimal. Iso

Other usage 1) Create a snapshot

QEMU-IMG snapshot-c name Sheepdog:myfirstdisk

View mirror list After snapshot creation

Collie VDI list name ID size used shared creation time Object ID--------------------------------------------------------- -----------Bob 0 2.0 GB 1.6 GB 0.0 MB 2010-03-23 16:16 80000 myfirstdisk 0 GB 0.0 MB 0.0 MB 2010-03-23 16: c0000 s Myfirstdisk 1 GB 0.0 mb 0.0 MB 2010-03-23 16:16 40000

To start a virtual machine with a snapshot

Qemu-system-x86_64 sheepdog:myfirstdisk:1 2) disk cloning

Qemu-img create-b Sheepdog:myfirstdisk Sheepdog:D Isk2 3) Close Sheepdog cluster

Collie cluster shutdown

This command closes the process for all nodes

4) Use fuse mount Sheepdog

First, create a volume named My_volume

echo My_volume >/Var/lib/sheepdog/vdi/mount

Format to EXT4 and Mount

Mkfs. Ext4/var/lib/sheepdog/volume/my_volume Mount-o loop/var/lib/sheepdog/volume/my_volume/mnt

When the connected sheepdog machine goes down we can switch online to another sheepdog

echo IP:p ort >/var/lib/sheepdog/config/sheep_info