第二部分
配置管理fault tolerance
fault tolerance的介绍
vmware ft is the evolution of "continuous availability"that works by utilizing vmware vlockstep technology to keep a primary machine and a secondary machine in a virtual lockstep.vmware ft will stream data that will be recorded,only nondeterministic events are recorede,and the replay will occur deterministically.by doing it this way,vmware has created a process that matches instruction-for-instruction and memory-for-memory to get identical results.
deteministic means that computer processor will execute the same instruction stream on the secondary virtual machine as to end up in the same state as the primary virtual machine.on the other hand,nondeterministic events are functions,such as network/disk/keyboard i/o as well as hard ware interrupts.so,the record process will take the data stream,and the playback will perform all the keyboards and mouse clicks.it is pretty slick to move the mouse on the primary virtual machine and see it also move on the secondary virtual machnie.
ft cluster级别的要求
1.host certificate checking must be enabled.this is the default for vcenter server 4.1 and later,but if you upgraded from an earlier version of vcenter server,you might need to enable this functionality.
2.the cluster must have at least two esxi hosts running the same ft version or build number.the ft version is displayed in the fault tolerance section of the esxi host's summary tab.(相同的ft版本)
3.vsphere ha must be enabled on the cluster.vsphere ha must be enabled before you can power on vsphere ft-enabled vms.(必须激活ha)
4.vmware evc must be enabled if you want to use vsphere ft in conjunction with vsphere drs.otherwise,vsphere drs will be disabled on any vsphere ft-enabled vms.(如果希望ft和drs联合工作,必须启用evc)
ft esxi host级别的要求
1.the esxi hosts must have access to the same datastores and networks.(访问相同的共享存储和网络)2.the esxi hosts must have a fault tolerance logging network connection configured.this vsphere ft logging network requires at least gigabit ethernet connectivity,and 10 gigabit ethernets is recommended.although vmware calls for dedicated vsphere ft logging nics,nics can be shared with other functions if necessary.(需要一个传输ft日志的网络连接)
3.the hosts must have cpus that are vsphere ft compatible.(兼容ft的cpu)
4.hosts must be licensed for vsphere ft.(支持ft的授权)
5.hardware virtualization(hv)must be enabled in the esxi host's blos in order to enable cpu support for vsphere ft.(在blos上启用硬件虚拟化hv)
最好单独拿一个网卡做ft log.
vm级别的要求
1.only vms with a single vcpu are supported with vsphere ft.vms with more than one vcpu are not compatible with vsphere ft.(只支持一个vcpu)
2.vms must be running a supported guest os.(运行支持的操作系统)
3.vm files must be stored on shared storage that is accessible to all applicable esxi hosts.vsphere ft supports fibre channel,fcoe,iscsi,and nfs for shared storage.(ft支持fc,fcoe,iscsi和nfs的共享存储)
4.a vm's virtual disks must be in thick provisioned(eagerzeroedthick) format for a virtual mode rdm,physical mode rdms are not supported.(虚拟机虚拟磁盘必须为"thick provisioned(预先置零)"
5.the vm must not have any snapshots.you must remove or commit snapshots before you can enable vsphere ft for a vm.(vm不能有快照)
6.the vm must not be a linked clone.(vm不能是linked clone)
7.the vm cannot have any usb devices,sound devices,serial ports,or parallel ports in its configuration.remove these item s from the vm configuration before attempting to enable vsphere ft.(vm不能有任何usb设备,声音设备,串口或者并口)
8.the vm cannot use n_port id virtualization(npiv).(不支持npiv)
9.nested page tables/extended page tables(npt/ept)are not supported. vsphere ft will disable npt/ept on vms for which vsphere ft enabled.(不支持npt/ept)
10.the vm cannot use nic passthrough or the older vlance network drivers.turn off nic passthrough and update the networking drivers to vmxnet2,vmxnet3,or e1000.(不支持nic passthrough和老的vlance的网络适配器)
11.the vm cannot have cd-rom or floppy devices backed by a physical or remote device.you'll need to disconnect these devices or configure them to point to an iso or flp image on a shared datastore.(不支持cd-rom和floppy设备连接到物理或远端设备)
12.the vm cannot use a paravirtualized kernel.turn off paravirtualization in order to use vsphere ft.(需要禁用"paravirtualization"技术)
ft的其他限制
1.it is recommended that power management(also known as power capping)be turned off in the blos of any esxi host that will participate in vsphere ft.this helps ensure uniformity in the cpu speeds of the esxi hosts in the cluster.(关闭电源管理)
2.while you can use vmotion with a vsphere ft-protected vm,you cannot use storage vmotion,by extension,this means that vsphere ft-protected vms canot take advantage of storage drs.to use storage vmotion,you must first turn off vsphere ft.(不支持存储vmotion和drs)
3.hot-plugging devices is not supported,so you cannot make any virtual hardware changes when a vsphere ft-protected vm is powered on.(不支持热插拔设备)
4.because snapshots aren't supported with vsphere ft,you can't back up vms using any backup methodology that relies on snapshots.this includes any backup solution that leverages the vsphere storage api for data protection as well as vmware data recovery.to back up a vsphere ft-enabled vm with one of these tools,you must first disable vsphere ft.(不支持快照,也不支持使用快照的备份技术,例如:vdr)
