University cloud and
virtualization
Tomáš Sapák
sapakt@ics.muni.cz
Cloud in theory
What is cloud?
- Private vs public
- Infrastructure as a service (IaaS) - Amazon Elastic
Compute Cloud, Google Compute Engine, Microsoft Azure, Open
Stack, Open Nebula
- Platform as a service (PaaS) - Google App Engine (PHP,
Python, Java, Go), Amazon Elastic Beanstalk (Ruby, PHP, Python,
.NET, JAVA, JavaScript), Microsoft Azure Websites (PHP, Python,
.NET, JavaScript)
- Software as a service (SaaS) - mail, social network,
on-line office, file services, image libraries, music libraries, video
libraries, web sites ...
NIST service model
IaaS at Masaryk university
- Infrastructure for production applications
- stable, highly available environment
for production level applications
- CERIT-SC cloud
- scientific computations with intensive
CPU workload
- covered in session by Aleš Křenek and
Tomáš Rebok
Infrastructure for production
applications
- virtualization (and consolidation) of physical
servers since 2006 on MU (VMware)
- most systems are nowadays virtualized
- Pros:
- easier management
- space and power consumption efficiency
- easy migration to different hw, location
- easier disaster recovery
- Cons:
- hw failures have worse consequences (Many
eggs in one basket)
Production infrastructure
- approximately 360 VMs
- critical systems (DNS, DHCP, E-mail, file
servers, databases, webservers ...)
- downtimes are not tolerable
- quality and redundant infrastructure is
essential
Components
- Physical servers
- Network
- SAN and storage
- Datacenters
- Virtualization layer
Physical servers
- core of virtual infrastructure
- diskless intel servers - virtual machines are
stored on disk arrays
- 9 hosts in production, 2 for testing, 2 in
secondary location, 2 in tertiary location
- evolution in form of number of cores (4 per
CPU in 2009 vs 10 per CPU in 2014) and
amount of RAM (48 GB per host in 2009 vs
384 GB per host in 2014)
Network
- 2x 10G Ethernet card per host
- each card is connected to different router
- active/active - all hosts can use both
interfaces for better performance (single
VM can use only one)
- 46 VLANs used by VMs
- Primary and secondary datacenter part of
same LAN
SAN
- storage area network
- dedicated network for storage traffic (between
storage arrays and hosts)
- 8G fibre channel
- fully redundant
- 2x fc switch, 2x hba port per host, per storage
array controller
- Connects primary and secondary datacenter
SAN
Storage
- all VMs are stored on disk arrays
- 3 mid-range arrays for VMs, several lowends
for large data and backups
- currently there are 2 tiered arrays, one of
them equipped with SSDs
Automated Storage Tiering
Traditional storage arrays problems:
- Expensive and low size of fast drives
(SSDs, FC, SAS)
- Low performance and long rebuild times
with high capacity SATA (NL-SAS) drives
Automated Storage Tiering
- Storage array consists of two storage layers
(tiers) with different types of disk drives (slow
and large, fast and small)
- Written data are partitioned and stored in the
fast tier
- For a few days usage of data is evaluated and
data with little usage are sent to lower tier
- For even better performance and space
utilization some vendors use different RAID
types for reading and writing
Automated Storage Tiering
Example
Storage of tommorow
- All flash array – online compression and
deduplication
- Virtual SAN
Datacenters
All datacenters are fully equipped with cooling,
UPS. Primary and tertiary locations have electric
generator for longer blackouts.
Primary location – ICS/FI building, Botanická.
Secondary location – University Computer
Center, Komenského, part of same LAN and SAN
as primary location
Tertiary location – University Campus Bohunice,
completely separated from primary and
secondary locations
Datacenters
Virtualization layer
- VMware vSphere 5.5
- VMware virtual infrastructure consists of
two fundamental elements – vCenter and
ESXi
- ESXi is hypervisor – software that creates
and runs virtual machines
- vCenter is central point for management of
hypervisors, virtual machines and users
Virtualization layer
- Primary and secondary datacenters
managed by single vcenter
- 13 hypervisors form 4 clusters:
- Production cluster
- Production cluster with special
demands
- Cluster for testing
- Cluster on secondary location
Features
Distributed resource scheduler (DRS):
– Automatically chooses less utilized host in
the cluster for newly started VM
– Automatically migrates VMs among nodes in
the cluster to balance load evenly
– Automatically migrates off VMs from
hypervisor for maintenance
High availability (HA):
- In case of failure of hypervisor automatically
powers on VMs on healthy hosts in the cluster
Features
Data Protection:
- Image-level virtual machine backup
(agentless)
- A few click restore
- Deduplication
- Changed Block Tracking Backup/Restore
Features
Replication:
- image-level replication
- Minimum 15 minutes RPO (Recovery Point
Objective)
- Not suitable for every application
- Eliminates single point of failure of storage
array (all other components are redundant)
Example
Features
Fault Tolerance:
- VM runs on two different hosts in the same
time
- In the case of host failure, failover is
automatically triggered – zero downtime
Overview
Thank you for your attention
Tomáš Sapák
sapakt@ics.muni.cz