dear techis, We are planningfor transition of exchnage server 2003 to2007. Exisiting setup : Exchange Server 2003 (TwoMailbox Cluster (Active & Passive infrastructure ) + (One front End Server )Planning for :Exchange server 2007 HUB + CAS both roles are installed on two Multiple machines [NLB configured on CAS Server ].multiple mailbox Server .Recently purchased an EMC San .Question :My question is related to get maximum highavailability by chose whether CCR OR SCC .EXISITING Users 4000 mailbox .planning for maximum 8000 mailboxes and we have to purchsed all new hardware for this transition phase .syed.arsalan

I would prefer CCR over SCC (if I have enough space to store database two times) because SCC provides server level highavailabilityand if database gets corrupted somehow then you will face Exchange service downtime (or limited service with dial tone method) and in background you need to reapir/restore the database since only one copy of database will be shared between both nodes. While CCR provides server as well as database level highavailabilitysince database will be replicated to second node of CCR over the wire through transaction logs under Exchangeintegritycheck so corruption will not be replicated and second database will be safe... Also adding SCR target, cas, hub and a DC at remote site, provides siteresiliency... Check Dougs below conclusion on a white paper. CCR or SCC? http://blogs.msdn.com/douggowans/archive/2009/03/18/ccr-or-scc.aspx High Availability http://technet.microsoft.com/en-us/library/bb124721.aspx Amit Tank | MVP Exchange Server | MCITP: EMA | MCSA: M | http://ExchangeShare.WordPress.com

Advantages of Cluster Continuous Replication over Single Copy Clusters

Dear Amit ,Thanks for valuable answers .Yes i am totally convinced with your ideas reagrding ccr .Now can youguide me that let suppose what we want to achieved is that we have recently purchased an EMC SAN ,can we used San with ccr and my conceptual dig is like that Site A (One City )Hub + Cas both roles installed simultaneaously on two machines ,FSW On Hub Transport Server .SingleMailbox Servers using CCR.(10.20.x.x)Edge Transport Server .(Responsible for inbound and outbound email traffic for whole org.Site BHub + Cas both roles installed simultaneaously on two machines .SingleMailbox Servers using CCR.(10.16.x.x)Question 1 :What happen if my site goes down and what happen regarding File shre witness because according my understanding FSW uses MNS Quroum in which it need maximum two nodes maximum ,initially if we not consider SCR so how this mechanism works .I have read little bit abt force quorum but my concept is not so clear as we bind the two servers for using FSW and what happen if one site goes down .Waiting for good reply.Thanks Syedsyed.arsalan

Sayed, I don't understand below lines, do you mean are you going to deploy only one physical node CCRin each siteinstead of two? SingleMailbox Servers using CCR.(10.20.x.x) SingleMailbox Servers using CCR.(10.16.x.x) You can put physical nodes of a CCR in different subnets if you are using Windows 2008 but AD site should be OEN to deploy CCR, so you need tostretchyour AD site between two datacenters if you are planning for geo-cluster CCR. Refer below couple of article for deep insight... Cluster Continuous Replication http://technet.microsoft.com/en-us/library/bb124521.aspx Planning for Cluster Continuous Replication http://technet.microsoft.com/en-us/library/bb123996.aspx Side-note: Physical nodes (up to 16) can be placed in any AD sites in Exchange 2010 DAG and can combine with HT & CAS roles, but it is still in Beta phase... Understanding Mailbox Database Availability http://technet.microsoft.com/en-us/library/dd351223(EXCHG.140).aspx Amit Tank | MVP Exchange Server | MCITP: EMA | MCSA: M | http://ExchangeShare.WordPress.com