"The latter - "we always have OS on a RAID1 set"." That's a fair argument - if the company has a hardware standard then it should be adhered to, if feasible. AD is just an app that sits on hardware as do other apps. Each app doesn't necessarily need a hardware spec all of its own.
Standards lead to lower TCO so it's always worth striving for. [Simpler procurement, support, maintenance etc] Caveat: On the flip side, we all to get the best from our solutions and the corp standard may not achieve that optimal 'best'. I've never encountered a large company who'll happily change or allow exceptions re hardware standards without a very strong argument. My 2 penneth, neil -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paul Williams Sent: 17 October 2006 14:31 To: ActiveDir@mail.activedir.org Subject: Re: [ActiveDir] Seperating Database and logs on seperate disks > What were the support reasons? Someone whined until they got the OS on > RAID-1 because that is the way "everyone" says they should do it or > another popular one is that is the way we "always" do it? The latter - "we always have OS on a RAID1 set". I've managed to swing RAID10 on the remaining 4 disks, and x64 and 32GB RAM. I can't get them (support folks) to take on support for pure RAID10. --Paul ----- Original Message ----- From: "joe" <[EMAIL PROTECTED]> To: <ActiveDir@mail.activedir.org> Sent: Tuesday, October 17, 2006 1:46 PM Subject: RE: [ActiveDir] Seperating Database and logs on seperate disks > What were the support reasons? Someone whined until they got the OS on > RAID-1 because that is the way "everyone" says they should do it or > another > popular one is that is the way we "always" do it? > > One of the issues is that most of the machines folks like to make into DCs > just don't have enough disk slots to have multiple spindles for the DIT if > you take up 4 for the OS and Logs. If you can get away with > mirror/mirror/6 > disk 0+1/10... Excellent, especially if x64 with sufficient RAM. If the > disk > counters start to show queuing on the DIT drive greater than what I > consider > heavy load (~2x#spindles) though I wouldn't hesistate to tear that down > and > make it into a single 10 disk RAID 0+1/10/5. With x64, as Paul indicated, > that generally shouldn't happen though unless you don't have enough memory > or possibly you have recently rebooted and are defrosting the cache. > > Mostly though, people should be looking at their own perf counters and > figuring out what they should be doing. Pay especially close attention to > Exchange GCs during the "morning rush" and the after lunch "rush", those > are > the two areas that tend to initially start showing pain. > > joe > > > -- > O'Reilly Active Directory Third Edition - > http://www.joeware.net/win/ad3e.htm > > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Paul Williams > Sent: Tuesday, October 17, 2006 5:03 AM > To: ActiveDir@mail.activedir.org > Subject: Re: [ActiveDir] Seperating Database and logs on seperate disks > > Having discussed this quite a lot recently, I'll give you all an insight > into how I wanted to do it and how we are doing it (support reasons caused > me to be overridden): > > [want] 6 disks in a RAID10 array, with three volumes: OS, DIT & Logs, > SYSVOL > > and Scratch area. > [reallity] 2 disks in a RAID1 array for OS; 4 disks in a RAID10 array for > DIT & Logs, with another volume for SYSVOL and scratch. > > > Scratch contains the IFM directory (temporarily) and perf logs, etc. > > I agree with Joe 100% (probably because we have discussed this offline in > depth and he has moulded my opinions <g> ). Smaller environments don't > need > > to worry about it. Big environments need to think about it. Although, as > Joe mentions, it's rare you'll need much space for the log files. Even if > you provision a couple of hundred thousand users (which takes an hour or > two) you don't need much space for logs. Which is why I hate the 3x RAID1 > idea that is out there. Disks are cheap for sure, but that's still a > serious waste of two disks where they could be put to use for the DIT, > which > > is being slammed with read requests. > > Also remember that in smaller environments, or medium-sized environments > that have didicated DCs, a DL360 (or equivalent) which only has room for > two > > local disks, will happily run as a DC. A couple of the smaller projects > I've worked on in the past (~7,000 users) we used just this. Although in > some of those we had to use DL380s at some of the branches as they were > also > > running Exchange! : ( > > One other thing I'd like to say here, is if you do need to worry about > separating your disks, then you really should be looking at x64. You get > better throughput with x64 on disk and memory access, and you also have > the > ability to get all, or at least a chunk of, your DIT data (as in objects > that matter to your and your queries) into RAM. Those disk specs above > are > being implemented with x64 dual-core, dual-proc systems with 32GB of RAM > as > our standard DCs. > > (What can I say, I have a reasonable sized DIT ;-) > > (or so I'm told...) > > > --Paul > > ----- Original Message ----- > From: "joe" <[EMAIL PROTECTED]> > To: <ActiveDir@mail.activedir.org> > Sent: Tuesday, October 17, 2006 5:36 AM > Subject: RE: [ActiveDir] Seperating Database and logs on seperate disks > > >>I am surprised there aren't more responses to this. >> >> My personal opinion is that a vast majority of installations don't need >> to >> separate off the logs for perf. In fact, I have often recommended running >> everything on a single RAID 0+1/10/5 (partition logically if you want to >> say >> separate off the OS and the AD stuff) to get better perf than splitting >> logs >> and OS off onto their own disks. Especially in larger orgs for Exchange >> GCs >> that tried to follow the deployment docs and do mirror, mirror, mirror or >> mirror, mirror, 0+1 but didn't have enough disks to get a good 0+1. >> >> In every case that I have had to review DCs with questionable disk >> subsystem >> perf, the issues are always around the DIT while the disks for the OS and >> the Logs are snoozing with IOPS sitting there not being used that could >> have >> saved the DIT from getting sucked into the mud. Rebuilding the disk >> subsystem with all disks in one of the above configurations has >> alleviated >> the issues in every case. Whether RAID 5 or 0+1/10 is faster you will >> want >> to test with your own disk subystems (say with IOMETER), it seems to >> vary. > >> I >> have seen RAID-5 faster and I have seen on different machines 0+1/10 >> faster. >> >> >> A case I am aware of where the logs definitely were good off on their own >> and would have seriously impacted perf if they weren't was Eric's DIT >> experiment where he built a 2TB DIT but he was adding objects at a very >> high >> rate of speed constantly for quite a while so the logs were being beaten >> pretty well. >> >> joe >> >> >> -- >> O'Reilly Active Directory Third Edition - >> http://www.joeware.net/win/ad3e.htm >> >> >> -----Original Message----- >> From: [EMAIL PROTECTED] >> [mailto:[EMAIL PROTECTED] On Behalf Of AD >> Sent: Monday, October 16, 2006 11:29 AM >> To: ActiveDir@mail.activedir.org >> Subject: [ActiveDir] Seperating Database and logs on seperate disks >> >> Is there any other reason other then performance to have the Active >> Directory log files and database on separate disks? >> >> Opinions are welcome. >> >> Thanks >> >> Yves >> List info : http://www.activedir.org/List.aspx >> List FAQ : http://www.activedir.org/ListFAQ.aspx >> List archive: http://www.activedir.org/ml/threads.aspx >> >> List info : http://www.activedir.org/List.aspx >> List FAQ : http://www.activedir.org/ListFAQ.aspx >> List archive: http://www.activedir.org/ml/threads.aspx > > List info : http://www.activedir.org/List.aspx > List FAQ : http://www.activedir.org/ListFAQ.aspx > List archive: http://www.activedir.org/ml/threads.aspx > > List info : http://www.activedir.org/List.aspx > List FAQ : http://www.activedir.org/ListFAQ.aspx > List archive: http://www.activedir.org/ml/threads.aspx List info : http://www.activedir.org/List.aspx List FAQ : http://www.activedir.org/ListFAQ.aspx List archive: http://www.activedir.org/ml/threads.aspx PLEASE READ: The information contained in this email is confidential and intended for the named recipient(s) only. 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