Domain controller down

[LukeC]

Hello,

After a bit of advice i have 3 dcs 2 are currently powered off with rest of the servers (no power on this site) We have physical one still powered on in a remote building (does not hold any fsmo roles) but only as a backup. Fully virtualised the dcs that are powered off are the fsmo role holders. They have been off since sunday. Im i to expect anything nasty to happen by leaving the physical powered on in remote building when these come back online.

[johnat1121]

Everything should be fine we have had a similar case with 5 DCs and two off, Domain Controllers will normally tombstone after 60 days, its only when they are rolled back that things can really hit the fan we had two off for about 30 days as the building was re-built and we turned them back on in a staggered manner we encountered no issues however it did take a while to replicate all of the changes.

[Blue_Cookeh]

FSMO roles can be offline for quite a while, if you suspect it's going to be more permanent then seize the roles onto the online DC whenever you have time. Also if those DCs are DNS servers your clients may be really slow resolving DNS queries.

 

Another thing to be wary of is your tombstone lifetime for DCs that are uncontactable. I would also advise bringing up 1 DC at a time when they do come back online.

[LukeC]

Thanks, hopefully we wont be off that long or if we are ill be implmenting the dr plan.

[unexus]

Hi All,

 

I hope you don't mind me hijacking this post but it seems like a good place to post this question.

 

I have 2 DCs; 1 Physical and 1 Virtual. Configuration is as follows:-

 

- Both are DNS servers

- The physical server is the DHCP server

- All clients "know" about both DNS servers (Checked by running ipconfig on the clients and checked the 005 and 006 entries in the DHCP scope)

- Both DCs are Global Catalogs (Checked in Active Directory Sites and Services)

- The physical server has all the FSMO roles (checked by running netdom query fsmo)

- The DCs are replicating properly - the most recent object changes made on the physical DC were also present on the virtual DC.

 

At 4am on Monday, the physical DC went down with a hardware fault. I fully expected the virtual DC to handle all login requests ... but no!! Pretty much every desktop login attempt resulted in "there are no logon servers available". I ended up getting the physical server back online at midday by which time there were some very tense teachers.

 

When everything had settled down, I ran DCDIAG on the virtual DC to see if there were any problems but all tests passed.

 

I'm a bit stuck as to why the virtual DC did not respond to the logon requests. Can anyone spot what I am missing here?

 

The only thing I didn't do was start the DHCP service on the Virtual DC, but I don't see why that would be needed as long as the desktops had a valid IP lease and both DNS servers configured.

 

Best Regards,

Keith.

[Mr.Ben]

Does the Virtual DC hold the Global catalog?

[twin--turbo]

Did you log onto one of those PC's localy and check it could ping the DC by IP and DNS?

 

TT

[twin--turbo]

Thing that springs readily to mind is a Short lease time on dhcp expired sleeping PC's.

 

why is the DHCP service not running on the vitrual?

 

TT