Adam Duffy Edina Public Schools

 The heart of virtualization is the “virtual machine” (VM), a tightly isolated software container with an operating system and application inside. Because each VM is completely separate and independent, many of them can run simultaneously on a single computer. A thin layer of software called a hypervisor decouples the VMs from the host, and dynamically allocates computing resources to each VM as needed.

 Why did we go with VMware vSphere?  What other options are available? ◦ Microsoft Hyper-V ◦ Xen (Citrix XenServer) ◦ KVM

 Server consolidation ◦ Fewer pieces of hardware to manage ◦ Reduce energy costs ◦ Take up less space in the server room ◦ Make more efficient use of hardware

 Hardware independence ◦ VMs can be moved between hosts with different hardware, thanks to the hypervisor  Entire system (OS, applications, and data) is contained in a set of virtual machine files. ◦ Provides flexibility in managing servers  Centralized server management

 If server hardware fails, how easily can you restore operations?  How much CPU and RAM is wasted in your traditional servers?  How much downtime do you experience if you have to replace or upgrade server hardware?  If software changes cause the server to fail, how easily can you recover?  How easily can you deploy a new server?

 Capture the state of a server at a point in time  You can safely make changes, knowing that you can revert back if something goes wrong  Integration with backups ◦ Snapshots themselves are not backups!

 Make a copy of a server without disturbing the live server  “Let’s try this”  Production -> development

 Have a pre-configured version of an OS ready to deploy  Ease of deployment opens up new possibilities

 Move VMs between hosts with no downtime  VMs are automatically restarted when a host fails  Automatically balance computing capacity across hosts

 Easily add CPU, RAM, HD space, NIC  Minimize downtime

 Some vendors provide premade VMs for deploying their services ◦ Cisco NCS  Collaborate with other districts ◦ Moodle VM

 Manage failover from production datacenters to disaster recovery sites  Periodic VM replication to DR site  Automated DR failover  Prioritize VMs

 Hardware ◦ Hosts  3x HP ProLiant DL380 G6  8x CPU cores per host, at GHz each  24 GB RAM per host ◦ Storage  2x HP StorageWorks P4300 G2 (LeftHand SAN)  5.5 TB usable  Software ◦ VMware vSphere 4

 Makes switching to virtual servers much easier  Can do it (mostly) live  Some success and some failure  Sometimes, it’s a good opportunity to rebuild

(dramatic reenactment)

 10 CPUs, 22 cores  Using 13.2 GHz / 97.5 GHz  288 GB RAM  Using 151 GB  34 TB usable storage  Using 24 TB  10 TB is high performance  44 virtual servers

 You’ll need outside help  May need to buy new hardware and software  Added complexity, new ways for things to go wrong  When not to virtualize

 Supports larger VMs ◦ Up to 1 TB RAM and 32 virtual CPUs  Improvements to HA ◦ Easier to set up, more scalable  vSphere Web Client

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