LlewellynIT
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Cost Effective Method to Achieve Redunancy/Failover for standalone Exchange
We have a standalone Exchange 2007 server setup in-house, combined with a few other physical servers that take care of the rest of the services (file sharing, DC, DNS, DHCP, etc). The server recently froze and caused us a few hours of downtime until we were able to respond. Because of this I have begun looking into options for redundancy and failover and Server 2008 with Hyper V seems to be a good bet, but I wanted the input of some experts if possible.
Our environment is as follows:
1 physical 32 bit Windows Server 2003, performing DC, DNS, WINS
1 physical 32 bit Windows Server 2003, secondary DC, DNS, BES
1 physical 64 bit Windows Storage Server 2003, file sharing
1 physical 64 bit Windows Server 2003, Exchange 2007, WSS 3.0
Our end goal is to have services that can failover if needed and stay up and running. My current plan is to turn each physical server into VHD's that can be loaded into Server 2008 Hyper V. I'll then be wiping the 4th server in the list and installing Server 2008 with Hyper V. From there I imagine I can load all the VHD's, but that then gives me a single point of failure if that hardware goes down. I've seen software that can replicate VHD's to another box running Server 2008 Hyper V, but is that the best and most cost effective solution to achieve this?
Our environment is as follows:
1 physical 32 bit Windows Server 2003, performing DC, DNS, WINS
1 physical 32 bit Windows Server 2003, secondary DC, DNS, BES
1 physical 64 bit Windows Storage Server 2003, file sharing
1 physical 64 bit Windows Server 2003, Exchange 2007, WSS 3.0
Our end goal is to have services that can failover if needed and stay up and running. My current plan is to turn each physical server into VHD's that can be loaded into Server 2008 Hyper V. I'll then be wiping the 4th server in the list and installing Server 2008 with Hyper V. From there I imagine I can load all the VHD's, but that then gives me a single point of failure if that hardware goes down. I've seen software that can replicate VHD's to another box running Server 2008 Hyper V, but is that the best and most cost effective solution to achieve this?
ASKER
So is the idea to have the servers hosting the Virtual Machines using an iScsi connection to the SAN? Any idea how to get a cost-effective SAN?
there is no such thing as a cost effective SAN.
upgrading to 2k10 is not cheap or simple either.
look at iscsi or if you dont have too many users then you may get by with a Dell MD3000 array. they cost about 12k. I know 12k isnt cheap but to upgrade to 2k10 will cost you more and a SAN is about 25-35k and you still need another server.
you can cluster with the MD3000 and the servers can hookup direct connect or using fibre, one or the other. fibre equals more money.
so you need another server built like the 4th server in your list and then look at an MD3000 array from Dell. then the data will be on the array and you will create a cluster with a virtual server. one passive box and one active box.
upgrading to 2k10 is not cheap or simple either.
look at iscsi or if you dont have too many users then you may get by with a Dell MD3000 array. they cost about 12k. I know 12k isnt cheap but to upgrade to 2k10 will cost you more and a SAN is about 25-35k and you still need another server.
you can cluster with the MD3000 and the servers can hookup direct connect or using fibre, one or the other. fibre equals more money.
so you need another server built like the 4th server in your list and then look at an MD3000 array from Dell. then the data will be on the array and you will create a cluster with a virtual server. one passive box and one active box.
You can get software from http://www.StarWindSoftware.com that can turn a Windows box into an iSCSI SAN for $995. They also have replication options. You can also use Linux for free to do the same thing. Remeber that vrtualizing and then clustering your virtual environment only solves some issues, mainly a hardware issue. Your guest can still blue screen, freeze, crash a service, or corrupt a database. The advantage is that it's usually easier to recover because the VMs boot faster, it's easier to make and restore a snapshot backup, it's easier to reboot a VM remotely, etc.
I suggest that you virtualize on R2, either Windows Server 2008 R2 Enterprise or Hyper-V Server 2008 R2. Hyper-V Server 2008 R2 is free, and well, Windows 2008 R2 Enterprise isn't (and you'll need two licenses for a two node cluster). Keep at least 1 physical DC (the second can be virtual). You can't boot a cluster without a domain controller running.
I suggest that you virtualize on R2, either Windows Server 2008 R2 Enterprise or Hyper-V Server 2008 R2. Hyper-V Server 2008 R2 is free, and well, Windows 2008 R2 Enterprise isn't (and you'll need two licenses for a two node cluster). Keep at least 1 physical DC (the second can be virtual). You can't boot a cluster without a domain controller running.
ASKER
I've read that virtualizing Exchange 2007 isn't a great idea for the mailbox database. So considering that it sounds like I need two physical machines, which sort of eliminates the purpose of virtualization for us.
My ultimate goal is I want to be able to bring our Exchange/Sharepoint back up VERY quickly. Currently we would have to restore from last night's backup using a bare-metal restore to another server. That involves 6-12 hours of downtime. There HAS to be a better option. Virtualization seems very expensive for a small company like ours, and in many cases won't work all the way (DC and Exchange).
My ultimate goal is I want to be able to bring our Exchange/Sharepoint back up VERY quickly. Currently we would have to restore from last night's backup using a bare-metal restore to another server. That involves 6-12 hours of downtime. There HAS to be a better option. Virtualization seems very expensive for a small company like ours, and in many cases won't work all the way (DC and Exchange).
look at creating a clustered exchange. one active server and one passive server. if a server fails the passive server picks up and you are back up and running within 2 minutes. then take your time and rebuild another server and add it back to the cluster.
true about the Dc comment but you can make a DC out of any cheap server. it doesnot have to be high end server for a DC.
and you will need enterprise exchange. it is more money but our company relies heavily on email to communicate with new customers and current customers. so the extra cost is worth it, for us. maybe not for your company. depends on how heavily your company uses email.
you could also look at hosted exchange, boooo Gmail or Google Apps.
true about the Dc comment but you can make a DC out of any cheap server. it doesnot have to be high end server for a DC.
and you will need enterprise exchange. it is more money but our company relies heavily on email to communicate with new customers and current customers. so the extra cost is worth it, for us. maybe not for your company. depends on how heavily your company uses email.
you could also look at hosted exchange, boooo Gmail or Google Apps.
I think that the performance penalties for running Exchange virtualized are overblown. I ran Exchange 2003 virtualized under MS Virtual server 2005 on non virtualization aware hardware for over 400 users and 100 BlackBerry users. I run Exchange 2007 under Hyper-V for 550 users with maybe 300 BlackBerries. The IO requirements for Exchange 2007 and 2010 are much less than Exchange 2003, so you should be fine as long as you can give a reasonable amount of RAM to your VMs.
ASKER
We have Exchange 2007 with 80 mailboxes, with a 4 GB limit each. Our primary server is a dual quad core xeon 2.5 ghz with 12 GB of RAM. I wanted to do virtualization because it made failovers sound easy to recover from, and would allow me to take full advantage of our only really powerful 64-bit server.
I don't need to do virtualization at all I guess, I just need a failover for Exchange/Sharepoint. I have a single core xeon as the storage server 2003 that's 64 bit and can probably support Exchange if needs be. Does that sound like a good candidate for a passive Exchange server?
How exactly does the passive Exchange work? Is this with mailbox database replication or something else?
I don't need to do virtualization at all I guess, I just need a failover for Exchange/Sharepoint. I have a single core xeon as the storage server 2003 that's 64 bit and can probably support Exchange if needs be. Does that sound like a good candidate for a passive Exchange server?
How exactly does the passive Exchange work? Is this with mailbox database replication or something else?
to have an active passive server setup the boxes need to be the same hardware wise and have the same apps installed. then you add an app to the cluster as a resource. so when it fails the cluster knows to activate the apps on to the new server.
so you need a 2nd box built like your current exchange box.
the passive and acitve server are always pinging each other, usually on the 2nd nic. if the passive does not get a return ping then it automatically takes over. its also handy when doing reboots or windows updates.
so you need a 2nd box built like your current exchange box.
the passive and acitve server are always pinging each other, usually on the 2nd nic. if the passive does not get a return ping then it automatically takes over. its also handy when doing reboots or windows updates.
ASKER
so I gather that built-in functionality of Exchange clustering will replicate the important stuff? my end goal is to have Exchange/Sharepoint failover to a passive server if the primary goes down. Sharepoint is less critical and if I had to restore from a previous night backup it wouldn't be that bad. Exchange on the other hand...
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ASKER
This data array can be a SAN, or file server, or NAS device I'm guessing? Most of my research has pointed at this solution as well, some type of shared storage so that no replication is needed.
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ASKER
Got it. Thank you for explaining the answer to this question in thorough detail, it is greatly appreciated. A SAN does indeed look pricey, so I'll probably be lining numbers up next to something like a NAS device and compare features/downtime potentials. Thanks again!
ASKER
The answer - there is no cost effective solution! The best solution and most consistent answer points to a shared data array, and virtualization/clustering of some kind.
My suggestion is to keep away from Virtaul Servers if you want to have peaceful sleep :)
VM are not recommanded to run high IOPS DB applications like exchange or SQL.
Now, you just had one down time.. But if it was in VM - you may hit with more issues.
Get a SAN box and have clustering.. Or upgraded to 2010 and have one more server to create a DAG where you dont require SAN - Just SATA disk will work.
Good luck
Shaba