xen virtualization 2008
DESCRIPTION
A presentation on Xen and Virtualization in general.TRANSCRIPT
The Main Players
Virtualization Awareness
Fully-virtualized All hardware fully emulated. Kernel is unaware it is virtualized.
Para-virtualized Kernel modified to be “aware” Direct access to some hardware
devices, so less emulation overhead.
CPU Technology: Intel-VT and AMD-V
What is it Good for? Efficient Hypervisor by eliminating
need to “trap and emulate”
End Result: Running an unmodified version of an
OS as a Guest.
When is Intel-VT and AMD-V Needed?
VMWare Xen32-bit 64-bit 32-bit 64-bit 32-bit 64-bit 32-bit 64-bit
Intel-VT No Yes No Yes Yes Yes No NoAMD-V No No No No Yes Yes No No
Unmodified Kernel Fully virtualized
Modified Kernel Para-virtualized
What am I getting into?
Why Use Virtual Technologies?
Implement High Availability
VM Guest stays up and running even if the physical Host machine goes down.
Requires: SAN Three or More Physical Hosts Clustered, Shared Filesystem
Increase Hardware Utilization
Run More on Less.
Boost CPU and RAM Utilization dramatically.
Take full advantage of RAM and Multi-core CPU’s.
Separate Service from Hardware
Liberate Windows Systems.
Backup and Restore a Fully configured system cheaply.
Upgrade hardware painlessly.
Business Continuity
Set up Once, distribute to multiple Data Centers.
Offsite Disaster Recovery through simple backup/restore process.
Load balance across Data Centers.
Try New Things
Provision New Servers within an Hour.
Teardown/Rebuild of Servers is highly efficient.
Clone and perform “dry-runs” before attempting on Production.
Getting Started…
Order of Importance: Sufficient RAM Fast Front-Side Bus (FSB) Fast Hard Drives and Controllers Multi-core CPU’s Cache memory CPU speed Network Bandwidth
Start Small…
Take a Desktop, install 2gb of RAM.
Install VMWare Server Free.
Install Windows and Linux as guest OS’s.
Get to know the terminology.
Try it in the Data Center…
Install Free versions of Xen or VMWare Server on an underutilized Server.
Bring up your new Service on VM Guests.
Get comfortable managing.
Learn to backup efficiently.
Make your Business Case…
Show your boss, make your case, get the equipment.
Convert oldest, slowest or most unstable servers first.
Save critical resources and high I/O systems (databases, file servers) for last.
Get used to diagnosing issues, pinpointing bottlenecks or stability issues.
Watch Your Performance Closely
Know when you’re saturating: Hard drive I/O throughput Network bandwidth CPU utilization
Commercial/Enterprise Licenses make this easier to monitor and manage.
For High Availability Dedicated iSCSI VLAN w/dedicated
NICs.
Line-speed, non-blocking switches
Host Bus Adaptors with TCP/IP offload Engines (TOE).
Wide-striped LUN’s.
Load-balancing Storage Processors on your SAN
What I’m UsingHardware Software
3 x Dell 2950’s 2 x quad-core Xeon 2.33ghz16-gb RAM4x250gb RAID 5 SCSIDual port iSCSI HBA
1 x Dell 29502 x quad-core Xeon 3.2ghz16gb RAM5x250gb RAID 5 SASDual port iSCSI HBA
1 x Dell AX150i2 storage processors12x500gb SATA II drives
2 x Dell 6248 GbE Switches
Linux:Oracle VM for Host
Fedora Core 8, CentOS 4, CentOS 5 Xen kernels for guests.
Red Hat’s Kickstart for provisioning new VM guests.
CentOS repositories to maintain patches on Oracle VM Host and CentOS guests.
Fedora Core repositories for FC8
Baphst01: xm list
Baphst01: xm top
What’s Running in our Environment?
Host Guests
Baphst01 18
Baphst02 10
Baphst03 19
Baphst04 15
Total 62
Apache ServersRails Application ServersContinuous Build ServersDNS ServersEmail ServersMySQL ServersPostgreSQL ServersSubversion ServerTrac Wiki ServersRepositoriesNagios
Maintenance Plan
Whenever Guest Images are provisioned or patched, Guest is downed and image backed up to SAN.
We use automated deployment tools and strict adherence to conventions to configure guest VMs and deploy our systems (Ruby on Rails).
Stress Rebuild over Restore.
Maintenance Plan
All config files kept in Subversion, which is hot copied to SAN via SAMBA shared resources.
Mysql, Postgresql and SQL Server 2005 backed up to SAN via SAMBA shared resources.
SAN backed up to portable 500gb USB drives via rsync.
Questions and Answers