When VMware released vSphere 5 last July (2011) the talk of the town was about the associated costs with the new memory licensing..
However there are many new features not available in version 4.
- In vSphere 5, storage resource management greatly improved with the introduction of Storage Distributed Resource Scheduler (DRS) as well as Profile-Driven Storage.
- Network I/O Control can help administrators prioritize VM traffic
- Mechanisms were redesigned for Storage vMotion
- There's now a new method for network packet receive processing improve efficiency.
Here are some of the main (more detailed) differences in this major release:
Improved storage resource management
In vSphere 5, storage resource management greatly improved with the introduction of Storage Distributed Resource Scheduler (DRS) and Profile-Driven Storage.
Storage DRS load balances automatically storage disks and selects optimized placement for VMs based on the available disk space and I/O loads.
These new capabilities fix the issues with DRS and Storage I/O Control in vSphere 4.
DRS only considers CPU and memory usage when load balancing, and Storage I/O Control can prioritize and limit I/O on data stores, but it doesn't allow you to redistribute I/O.
Storage DRS can also use Storage vMotion to load balance data stores, based on storage space utilization, I/O metrics and latency.
Another feature is Storage Profiles, which allows you to define classes of storage so VMs are provisioned and migrated to the proper storage type. Many infrastructures have multiple storage data stores with different performance characteristics. Storage Profiles makes sure a VM stays in a class of storage that the administrator specifies.
Fault Domain Manager
VMware High Availability (HA) has been completely overhauled, however it's now quite complicated!
Previously, VMware HA relied on up to 5 primary nodes to maintain the cluster settings and node states. The other hosts were secondary nodes and sent their states to the primary nodes. Communication between the primary and secondary nodes involved heartbeats, which could detect outages.
In the new HA architecture, each host runs a special Fault Domain Manager agent that's independent of the vpxd agent, which is used to communicate with vCenter Server.
It also uses a master/slave concept, with one host elected as a master and the other hosts as the slaves. The election uses an algorithm to determine the master and it occurs at several stages: when HA is enabled, when a master fails or is shut down, or when a problem occurs with the management network.
Perhaps one of the best changes to HA is that it no longer relies only on the management network to monitor the heartbeats. HA can now use a storage subsystem for communication,(Heartbeat Datastores - which are used as a communication only when the management network is lost. VCenter Server automatically chooses two data stores to use for monitoring)
ESX is a gonner, as well as the Service Console!
Finally, after years of talk, the only hypervisor is now ESXi.
There are two major differences between ESX and ESXi: installation and command-line management.
Manually installing ESXi is easier, and the wizard is simple (compared to ESX).
For automatically deploying ESXi, new auto deploy options can PXE (Preboot Execution Environment) boot and load images for ESXi installations.
As far as CLI, there's no longer have a full service console. Most management can be done remotely with vSphere CLI and vMA. The esxcli command has been expanded quite a bit in vSphere 5 to provide more manageability and it's supposed to eventually replace the existing vicfg-* management commands.
Memory based licenses
VSphere 5 licenses come with restrictions on the amount of CPU sockets and memory that you can allocate to virtual machines (VMs), although VMware has lifted the limitation on the number of CPU cores that can be used.
A Standard license allows you to allocate 16GB of RAM and 1 CPU socket to powered-on virtual machines (VMs), it doesnt care how much physical memory a host has.
An Enterprise license allows 32GB allocation of memory and 1 socket, and
Enterprise Plus allows 48GB allocation of memory and 1 CPU socket.
For example, if a host has Enterprise Plus licenses for two, physical processors, you can allocate 96GB of RAM to divide among VMs.
It's going to be very expensive to scale up hosts by adding large amounts of memory. Preventing VM sprawl and sizing the resources of individual VMs is much more important now, with these new licensing mechanisms.
Upgraded vCenter Server and Web client
With this new release, vCenter can be deployed as a Linux virtual appliance. The appliance maintains all the regular vCenter Server features, except for Linked Mode
VCenter now comes packaged with a DB2 Express database. It also supports only Oracle or DB2 external databases.
VMware has also updated the Web client which can be used for various administration tasks. The old Web interface was not very useable. I didnt know anyone that really used it.
Take a look at my article on Adding a VM to a VMware 5