We have allot of users coming back to our central site and
we use the following config.
adapter #1 ====> raid 1 ( 2 disk)
O/S
adapter #2 ====>raid 1 ( 2 disk) AD
LOGS
adapter #3 ===> raid 5 (3 disk) with
global hot spare AD Data
the key to this using this is that all the equipment (SCSI
disk,SCSI controller) is Ultra 320 spec with low latency and low seek
times (15 K rpm usually). The other thing that has been
noticed is that use as small a disk as you can get. (8 GB)
Some of the manufacturers are saying they only can supply 36GB drives on new
equipment. These drive are ok but the seek time goes up because of
the size of the drive
this config works good also
adapter #1 ====> raid 1 ( 2 disk)
O/S
adapter #2 ====>raid 1 ( 2 disk) AD
LOGS and raid 5 (3 disk) with global hot
spare (total of 6 on this channel)
hope this
helps
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LOL. I actually pinged Rick on the "official" guidelines
previously for an Enterprise class DC with 4 disks, he was actually one of 4
people I queried since I hadn't seen what I considered good official docs on it.
Rick quoted the K3 Deployment guide which is definitely a good start. It
indicates
RAID 1 - OS
RAID 1 - Logs
RAID 1 or 0+1 - SYSVOL/DIT
If you have less than 1000 users using the DC it says you
can use one single RAID-1 for the whole thing. Though you have the same issue
here as you have for anything, how are the 1000 users using it and what else is
using it? Exchange? If so, I doubt I would do a single RAID-1 unless it was very
few users.
Otherwise you are looking at a minimum of 6 disks for all
RAID-1s or 8 disks if 0+1 and RAID-1.
When you actually look at it, the OS and the logs are using
little IOPS on a dedicated DC and splitting them off onto their own "disk" is
probably unneccessary. The DIT assuming it isn't all cached and is being heavily
hit (like say by Exchange) is raping the disk subsystem. When you have an app
that wants lots of IOPS what do you? You increase the number of spindles... So
for throughput, the fastest four disk configuration is going to
be a RAID-5 or a 0+1 or 10. In tests I did several years ago with one
hardware vendor RAID-10 and 5 were very close (within a few IOPS) with
RAID-5 eeking out the lead. They both blew RAID-1 away. In more recent tests I
heard of from someone using another hardware vendor, RAID 0+1 eeked out over
RAID-5 by a few IOPS and again blew RAID-1 out of the water. Obviously the
tests were different so I recommend folks do their own testing with their own
hardware. The fastest disk configs I am aware of are 6 and 8 disk RAID-10/0+1
setups with 8 disks supposedly being rock star fast if you have the room
internally. To put it another way, if I had 8 disks, I certainly wouldn't be
following the deployment guide config for those disks, it would be a RAID-10/0+1
setup. The 6 disk RAID-10s (The Dells I was using then didn't support 0+1) I
built about 3 or 4 years ago were screaming fast compared to everything else at
the time I had worked with. Now I don't do anything with hardware, I am more
cerebral. ;o)
And note, obviously I am not talking software RAID, this is
all hardware. Software RAID isn't something you use for production machines IMO.
joe
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rick Kingslan Sent: Sunday, November 06, 2005 10:17 AM To: ActiveDir@mail.activedir.org Subject: RE: [ActiveDir] Raid suggestions for DC maybe OT Dan - there will likely be as many opinions on this topic
on this list as there are knots on joe's head.
Basic rules for a DC are this (IMHO):
Mirrored (or RAID1) for OS
Mirrored (or RAID1) for DIT and Logs
You can certainly host a third mirrored pair for the logs,
but that will mostly depend upon how BUSY your AD is and how high the
replication traffic, changes, updates etc. that you
experience.
If you're asking this, you most likely have a newer AD, or
are re-architecting. In either case, I'd start with the above and then
monitor the performance with PerfMon. Make some decisions on whether to
ADD the third mirror based upon the I/O and performance impact of log writes vs.
impact on the database reads/writes.
Hope this helps!
Rick [msft]
-- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Dan Cox Sent: Sunday, November 06, 2005 1:31 AM To: ActiveDir@mail.activedir.org Subject: [ActiveDir] Raid suggestions for DC maybe OT What would be the suggested RAID and partitioning
scheme for a Domain controller.
Any suggestions are appreciated.
Thanks. Dan Cox
|
- RE: [ActiveDir] Raid suggestions f... Carr, Jonathan \(OFT\)
- RE: [ActiveDir] Raid suggesti... joe
- RE: [ActiveDir] Raid sugg... David Adner
- Re: [ActiveDir] Raid sugg... Phil Renouf
- RE: [ActiveDir] Raid suggesti... Bahta Nathaniel V Contractor NASIC/SCNA
- RE: [ActiveDir] Raid suggesti... Grillenmeier, Guido
- RE: [ActiveDir] Raid suggesti... Carr, Jonathan \(OFT\)
- RE: [ActiveDir] Raid sugg... joe
- RE: [ActiveDir] Raid sugg... Rick Kingslan
- RE: [ActiveDir] Raid suggesti... Ed Crowley [MVP]
- RE: [ActiveDir] Raid suggesti... Carr, Jonathan \(OFT\)