Shared Machine Room / Service Opportunities. Bruce Campbell November, 2011

Transcription

1 Shared Machine Room / Service Opportunities Bruce Campbell November, 2011

2 Overview / Motivation Efficiencies Disaster Recovery

3 First a bit about servers/storage/backups/redundancy Example: Non redundant server with tape backup Upon failure, install new server and operating System, restore data from tape.

4 Adding Redundant Components Server can be built with internal redundant disk drives (RAID), redundant fans and power supplies. This reduces the probability of complete failure, and/or allows live replacement of failed components. Response to total failure still involves complete rebuild and restore.

5 Disaster Recovery The previous approach may be adequate for failures of single servers, a staff member can spend the day rebuilding the single failed server. Not scalable to failure of hundreds of servers (complete data centre) at same time because time to recover is unacceptable.

6 Redundant Data Centres and Services Two data centres in different buildings Fire anywhere in a building can render complete building inaccessible (ventilation/cooling shutdown, possible loss of power). Server redundancy approaches: Pairs of servers providing dedicated function. E.g. pair of web servers, kept synchronized. Many services designed for this type of operation (e.g. DNS, DHCP, domain controllers, database servers) Redundant externalized storage (e.g. SAN). Still need to think about redundant server hardware, design considerations (e.g. application redundancy mechanisms, active/active vs active/passive) Virtualization with redundant servers and redundant storage. Layer of abstraction between operating system and hardware.

7 Redundant Virtual Servers with Operating Systems and Applications are essentially unaware they are running on redundant hardware in multiple buildings Operating System and Application managers do not need to think (a lot) about redundancy, it is solved once at the storage layer But, not all applications are good candidates for virtualization Redundant Storage

8 IT groups providing critical services require: Redundant data centres in two different buildings Redundant servers, storage, and backups Mechanisms: Use high availability features of services where they exist (e.g. database cluster features) Virtualize as much as possible, with redundant compute clusters and redundant storage Handle remaining cases (not good virtualization candidates, no HA built in) with redundant hardware and custom tools/scripts to synchronize

9 IST Services , web content management and active directory are provided centrally (or are in progress). This reduces the amount of critical infrastructure in faculty machine rooms. Consider further leveraging of suitable IST services (e.g. storage) Consider leveraging IST s virtualized environment. Enumerate remaining critical services, is there opportunity for collaboration with other groups?

10 Machine Rooms Consider use of IST machine room space Consider shared network design to facilitate sharing multiple IT groups machine rooms. (in this model, IST provides central routing, network load balancing, firewall services, and connects faculty machine rooms. Equipment can be located in multiple faculty machine rooms (and use layer 2 redundancy mechanisms), and be protected by IST managed firewalls)

11 Shared Machine Room Network Core FW SLB FW SLB sers servers AHS users servers Arts IST Machine Rooms users servers Engineering users servers

12 Shared Machine Room Network Allows equipment to be located in any campus machine room Shared virtualization infrastructure possible Virtual machines from a lost faculty datacentre could be migrated to another faculty, or IST, and brought back up (with advance planning and agreement on technology) Component count is N+1 rather than 2N Shared virtualization infrastructure may be attractive for groups that have investment already, or wish to stay directly involved. Pros/cons compared to fully centralized infrastructure should be enumerated, in any case.