1. What are the vision and Goals of Exchange Server 2010 high availability?Vision – deliver a fast, easy to deploy and operate, economical solution that can provide high availability solution for exchange server
Goals – Achieve below details
1. Deliver a high availability and site resilience that is native to exchange
2. Enables less expensive and less complex storage
3. Simplify administration and reduce support cost
4. Increase end-end availability
5. Support exchange server 2010 online
2. What are the high availability solutions introduced in Exchange Server 2010?
- Unified technology for high availability and site resilience
- New framework for high creating high available mailboxes
- Evolution of continuous replication
- Can be deployed on a range of storage option
3. What are the High Availability features introduce in Exchange Server 2010?Mailbox resiliency – unified high availability and site resiliency
Database Availability Group – a group of up to 16 Mailbox servers that holds the set of replicated databases
Mailbox database copy – a mailbox database (.edb files and log file) that is either active or passive copy of the mailbox database
Database Mobility – the ability of a single mailbox database to be replicated to and mounted on other mailbox servers
RPC Client Access Service – a Client Access Server feature that provides a MAPI endpoint for outlook clients
Shadow redundancy – a transport feature that provides redundancy for messages for the entire time they are in transit
Incremental deployment – the ability to deploy high availability or site resilience after the exchange is installed
Exchange third party replication API – an exchange provided API that enables use of third party replication for DAG
4. What is high availability?High Availability is a solution that provide data availability; service availability and automatic recover from site failures
5. What is disaster recovery?It is a procedure used to manually a recover a failure
6. What is site resilience?Site Resilience is a disaster recovery solution used for recovery from site failure
7. What is switch over and failover?A
switch over is a manual activation one or more databases when failure occurs
A
failover is an automatic activation of one or more databases after failure
8. What are the concepts deprecated in Exchange Server 2010?
- Storage groups
- Database identified by the servers which they live
- Server names as part of database name
Clustered Mailbox server
- Pre-installation of failover cluster
- Running setup in failover mode
- Moving a CMS identity between servers
- Shared storage
Two high availability copy limits
Private and public networks
9. Explain new features in Exchange Server 2010 High Availability?1. No need to failover a server if a single database fails
2. Failover and switchover occurs at the database level and not the server level
3. With the new HA feature; we can have 100 databases per server
4. Databases are tied to specific server can be float across servers in organization
10. Give an idea on Exchange server 2007 High Availability Architecture changes?In exchange server 2007 HA, there are four HA features available, they are LCR, SCR, SCC and CCR. The concept of LCR and SCC has been completely removed in Exchange server 2010. The concept of SCR and CCR are incorporated with the new HA feature (Database Availability Group) in Exchange Server 2010.
11. What is Auto Database Mount Dial in Database Availability Group?If the Mailbox Database on a DAG is replicated to other server and if a failure occurs, an automatic recovery will occur or a manual recover needs to be performed by administrator. Auto Database Mount Dial is a predefined settings that are used when Automatic recovery occur if any failure happen to the replicated databases on a DAG.
The settings are nothing but a option that informs, how many logs can be ignored while activating a passive copy, if any failure occur to the active copy.
Default Auto Database Mount Dial Settings
- Good Availability (Default) – 6 or fewer logs can be missing when mounting a passive copy
- Best Availability – 12 or less logs
- Loss less – Zero logs missing
- Best effort – there is no specification; it will mount the passive copy. It will be used when switch over occurs
12. What are the continuous replication modes available in Database Availability Group?There are two types of replication modes in Exchange server 2010 SP1 release
File Mode – it is the normal or default mode of continuous replication to ship the log files. Passive copy ask for the logs from the active copy by informing that I have these many logs and send me new logs if you have.
Block Mode – on the initial stage of replication, file mode will occur and once the passive copies is similar to active copy and copy queue length is zero, then block mode starts. Block level (log buffer data shipping) log shipping
13. What is a quorum?Quorum is a cluster component and if we take a 5 node cluster, quorum is the component to ensure that only one node is active or functioning at a time
Quorum is that data that is shared between the voters, representing configuration information. It is number of voters that is required for a solution to be running
In simple: When a majority of voters can communicate with each other, the cluster has quorum
When a majority of voters cannot communicate with each other, the cluster does not have quorum
14. What are Witness, Witness Server and Alternate Witness Server?Below are the details of Witness, witness Server and Alternate Witness Server
Witness:A witness is a file share on a server that is external to the DAG that participates in quorum by providing a weighted vote for the DAG member that has a lock on the witness.log file. Witness is configured for all the DAG but it is used only when the DAG have the even number of members.
Witness Server:Witness Server is a normal server, which is external to the DAG that holds a file share having the Witness log file in that. Witness server does not maintain a full copy of quorum data and is not a member of the DAG or cluster. Witness Server should be located on the same active directory forest. There is no restriction for this server to be only a Hub Transport server.
Alternate Witness Server:As the name implies, the alternate witness server is not the alternate server for the existing witness server. It is the witness server used by the DAG, when a data centre switcher happened.
DAG does not have the ability to automatically switch over the alternate witness server, if the active data centre goes down. Exchange admin has to involve in activating the alternate witness server.
It will not provide redundancy for witness server or file share witness server recover.
15. What is Active Manager? What are the types of Active Manager available?In Exchange 2010, we don’t have the cluster model to achieve the High Availability. Active Manager is the new exchange server DAG component that manages the high availability platform. The failover and the switchover are managed by Active Manager.
Active Manager runs on every mailbox server
Active Manager holds the information of, in which server the active copy of a database is mounted and it will store this information in cluster database and it will share the same information to other active manager running on other mailbox servers in a DAG
There are 3 types of Active Manager available in Exchange 2010
- Standalone Active Manager – AM runs on each mailbox server
- Primary Active Manager – AM runs on the DAG that holds the cluster resource group
- Standby Active Manager – AM runs on every other node on the DAG