RE: [ActiveDir] NTDS.DIT Size

[Grillenmeier, Guido]

1.7GB for 250.000 users is pretty small already - I guess you don't use Exchange for messaging or use extremely few attributes of your objects in AD.  With the steps outlined by Ulf you should get a fair idea on how much whitespace you currently have, however, you shouldn't expect to have much if your AD is growing at a fairly constant rate. The database grows fairly linear and whitespace is being used automatically be new data.   As you're talking about moving to 64-bit, I guess you're already using Win2003.  On 32-bit Windows 2003 DCs without /3GB switch, the LSASS process can consume (cache) up to about 1.5GB, with /3GB it's around 2.6GB.  /3GB is supported on both Standard and Enterprise Edition with respect to DCs.   So theoretically you're well in the limits of the 32-bit OS, as long as you have at least 4GB in your DCs and are using the /3GB switch.  However, the /3GB switch reduces the vitual memory for the kernel down to 1GB, with can be a limiting factor in other situations - usually not on a DC (if it's not also hosting many other services).   But the 64-bit DCs won't cost you one penny extra: almost all server HW for the past 12 months has been x64 capable and the 64-bit Win2003 version has the same licensing costs as the 32-bit version. So you might as well go for it and have even more room for growth.  Mind you, with your current DIT size you should not expect much performance difference for your AD (unless you're replacing old server HW with new HW at the same time...). /Guido From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ulf B. Simon-Weidner Sent: Donnerstag, 29. Juni 2006 23:47 To: ActiveDir@mail.activedir.org Subject: RE: [ActiveDir] NTDS.DIT Size Hello Joshua,   I’d look at the whitespace to determine when to offline defrag a DC. You can enable the associated event which will tell you the amount of whitespace by setting the registry key HKLM\System\CurrentControlSet\Services\NTDS\Diagnostics\6 Garbage Collection to 1 instead of 0 (which is the default). Regkey might be likely – just typed it from hard. This will give you an event every time when garbage collection runs (every 12 hrs) and tell you the amount of whitespace in the DB.   Whatever needs to be loaded should perform better when smaller.   I’ve heard that a DC on x64 will perform better than on 32-bit, since it’s very likely you already have some of the newer servers with x64 I’d just give it a try for one DC yourself.   Gruesse - Sincerely, Ulf B. Simon-Weidner   Profile & Publications:   http://mvp.support.microsoft.com/profile="">      Weblog: http://msmvps.org/UlfBSimonWeidner   Website: http://www.windowsserverfaq.org From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Joshua Coffman Sent: Thursday, June 29, 2006 10:59 PM To: ActiveDir@mail.activedir.org Subject: [ActiveDir] NTDS.DIT Size   Our AD (NTDS.dit) is at 1.7GB (approx. 250,000 users).   Should an offline defrag be performed at a regular interval?   Some articles I read only say it is only worthwhile if you are running low on space. We have plenty of drive space and RAM.   At what point should the AD be moved to 64 bit?   Thanks,   Josh