Which DC do I demote first?

Hi,

In our current environment we have DC1 and DC2. DC1 being the 'master' DC.

We have successfullly migrated to a new DC (transferred DHCP, AD, FSMO roles
and DNS) as follows:

DC1 (Win Server 2003) -> migrated to new DC3 (Win Server 2008 R2)

We also have DC4 which is the new secondary DC that DC3 will replicate to:

DC2 (Win Server 2003) -> will be new DC4

When it comes to demoting the old DCs, which should we demote first?Do we
demote DC1 then DC2 or the other way around? Does it matter?

Any advice would be much appreciate.
Many thanks
Mehds

Hello Mehdis,

Make sure the domain is healthy with the support tools:
dcdiag /v /c /d /e /s:dcname >c:\dcdiag.txt
netdiag /v >c:\netdiag.txt [from each DC, netdiag may work but isn't supported
with Windows server 2008 and higher]
repadmin /showrepl dc* /verbose /all /intersite >c:\repl.txt (if more then
one DC exists)
dnslint /ad /s "DCipaddress" (http://support.microsoft.com/kb/321045)

If errors occur post them to Windows sky drive. As the output will become
large, DON'T post them into the thread, please use Windows Sky Drive. Also
the dcdiag scans the complete forest so better run it on COB.

After the domain is checked make sure that the new DCs also DNS server(AD
integrated zones) and Global catalog server. All domain members should only
use the new DNS servers on the NIC or via DHCP scope options.

Now you should disconnect the old DCs 1-2 days to see if still everything
is working as expected, then reconnect and run dcpromo on them to demote
them, after succesful demotion remove them manual from AD sites and services,
not done during demotion. If you have also removed them complete from AD
UC after demoting check DNS zones also that they aren't listed any longer.

Best regards

Meinolf Weber
Disclaimer: This posting is provided "AS IS" with no warranties, and confers
no rights.
** Please do NOT email, only reply to Newsgroups
** HELP us help YOU!!! http://www.blakjak.demon.co.uk/mul_crss.htm


> Hi,
>
> In our current environment we have DC1 and DC2. DC1 being the 'master'
> DC.
>
> We have successfullly migrated to a new DC (transferred DHCP, AD, FSMO
> roles and DNS) as follows:
>
> DC1 (Win Server 2003) -> migrated to new DC3 (Win Server 2008 R2)
>
> We also have DC4 which is the new secondary DC that DC3 will replicate
> to:
>
> DC2 (Win Server 2003) -> will be new DC4
>
> When it comes to demoting the old DCs, which should we demote first?Do
> we demote DC1 then DC2 or the other way around? Does it matter?
>
> Any advice would be much appreciate.
> Many thanks
> Mehds

As long as you have dc/dns services available it shouldn't really matter. I
have an article to help with the demotion process you may want to read.

http://www.pbbergs.com/windows/articles.htm
Select Decommission a DC

--
Paul Bergson
MVP - Directory Services
MCITP - Enterprise Administrator
MCTS, MCT, MCSE, MCSA, MCP, Security +, BS CSci
2008, Vista, 2003, 2000 (Early Achiever), NT4
Microsoft's Thrive IT Pro of the Month - June 2009

http://www.pbbergs.com Twitter - @pbbergs

Please no e-mails, any questions should be posted in the NewGroups. This
posting is provided "AS IS" with no warranties and confers no rights.
"Mehdis" <> wrote in message
news:BA6FA1A7-DDCB-448F-95F3-...
> Hi,
>
> In our current environment we have DC1 and DC2. DC1 being the 'master' DC.
>
> We have successfullly migrated to a new DC (transferred DHCP, AD, FSMO
> roles
> and DNS) as follows:
>
> DC1 (Win Server 2003) -> migrated to new DC3 (Win Server 2008 R2)
>
> We also have DC4 which is the new secondary DC that DC3 will replicate to:
>
> DC2 (Win Server 2003) -> will be new DC4
>
> When it comes to demoting the old DCs, which should we demote first?Do we
> demote DC1 then DC2 or the other way around? Does it matter?
>
> Any advice would be much appreciate.
> Many thanks
> Mehds

Many thanks for the advice Meinolf and thanks for the info on the link Paul.
Will give these a try very soon hopefully.

"Meinolf Weber [MVP-DS]" wrote:

> Hello Mehdis,
>
> Make sure the domain is healthy with the support tools:
> dcdiag /v /c /d /e /s:dcname >c:\dcdiag.txt
> netdiag /v >c:\netdiag.txt [from each DC, netdiag may work but isn't supported
> with Windows server 2008 and higher]
> repadmin /showrepl dc* /verbose /all /intersite >c:\repl.txt (if more then
> one DC exists)
> dnslint /ad /s "DCipaddress" (http://support.microsoft.com/kb/321045)
>
> If errors occur post them to Windows sky drive. As the output will become
> large, DON'T post them into the thread, please use Windows Sky Drive. Also
> the dcdiag scans the complete forest so better run it on COB.
>
> After the domain is checked make sure that the new DCs also DNS server(AD
> integrated zones) and Global catalog server. All domain members should only
> use the new DNS servers on the NIC or via DHCP scope options.
>
> Now you should disconnect the old DCs 1-2 days to see if still everything
> is working as expected, then reconnect and run dcpromo on them to demote
> them, after succesful demotion remove them manual from AD sites and services,
> not done during demotion. If you have also removed them complete from AD
> UC after demoting check DNS zones also that they aren't listed any longer.
>
> Best regards
>
> Meinolf Weber
> Disclaimer: This posting is provided "AS IS" with no warranties, and confers
> no rights.
> ** Please do NOT email, only reply to Newsgroups
> ** HELP us help YOU!!! http://www.blakjak.demon.co.uk/mul_crss.htm
>
>
> > Hi,
> >
> > In our current environment we have DC1 and DC2. DC1 being the 'master'
> > DC.
> >
> > We have successfullly migrated to a new DC (transferred DHCP, AD, FSMO
> > roles and DNS) as follows:
> >
> > DC1 (Win Server 2003) -> migrated to new DC3 (Win Server 2008 R2)
> >
> > We also have DC4 which is the new secondary DC that DC3 will replicate
> > to:
> >
> > DC2 (Win Server 2003) -> will be new DC4
> >
> > When it comes to demoting the old DCs, which should we demote first?Do
> > we demote DC1 then DC2 or the other way around? Does it matter?
> >
> > Any advice would be much appreciate.
> > Many thanks
> > Mehds
>
>
> .
>