Disk Configuration for AD domain controllers

We have two Dell PE1950's with mirrored 73gb drives and 2gb of memory. We
need guidance for configuring the disk drives. These two servers will be our
AD domain controllers and will also have integrated DNS.

My questions are as follows:
1. I read that it is recommended to store the AD database and logs on a
separate disk from the OS. Since I don't have the luxury of two separate
disks, is it ok to create on large partition for the OS, db and logs or
should I create two separate partitions?

2. I have already used these servers (using one large partition for the os,
db and logs) for testing my upgrade path from NT4 to Win2k3 AD. During the
tests I noticed the following error on both servers:
"Event ID 1539

The local domain controller could not disable the software-based disk write
cache on the following hard disk.

Hard Disk:

C

Data might be lost during system failures."

Doing google searches I believe this error is because the db and log files
are on the same partition as the OS. I also came across notes on disabling
write cache but it is still unclear to me what my best option is. Should I
leave the write cache enabled or should I disable it on the RAID controller?
I looked at the Dell Open Manage logs for the hardware and the RAID
controllery battery is fine and there are no raid or hard drive errors.

Thanks in advance for any assistance.

 

In line...
"Caryn Condon" <CarynCondon@discussions.microsoft.com> wrote in message
news:B62FBC22-544C-4CB8-A779-91BD134E6FC1@microsoft.com...
> We have two Dell PE1950's with mirrored 73gb drives and 2gb of memory. We
> need guidance for configuring the disk drives. These two servers will be
> our
> AD domain controllers and will also have integrated DNS.
>
> My questions are as follows:
> 1. I read that it is recommended to store the AD database and logs on a
> separate disk from the OS. Since I don't have the luxury of two separate
> disks, is it ok to create on large partition for the OS, db and logs or
> should I create two separate partitions?

AD is organized and works as a database, hence the recommendation.
However, AD is not such a large database as Exchange for example.
It is safe to keep AD database and log on the OS volume.

>
> 2. I have already used these servers (using one large partition for the
> os,
> db and logs) for testing my upgrade path from NT4 to Win2k3 AD. During the
> tests I noticed the following error on both servers:
> "Event ID 1539

<snip>

Due to the way the databases work http://en.wikipedia.org/wiki/ACID , the OS
will try to disable write cache to avoid database inconsistencies if a
sudden break occurs in the middle of transaction.

If your RAID controller has a battery backup, it is usually safe to leave
write cache enabled on the disk.

> Doing google searches I believe this error is because the db and log files
> are on the same partition as the OS. I also came across notes on disabling
> write cache but it is still unclear to me what my best option is. Should I
> leave the write cache enabled or should I disable it on the RAID
> controller?
> I looked at the Dell Open Manage logs for the hardware and the RAID
> controllery battery is fine and there are no raid or hard drive errors.
>
> Thanks in advance for any assistance.

AD is rather robust and now a mature and well known technology. If you have
two DC's in your domain and good, regular, trouble free replication between
them, your domain will have a high level of fault tolerance and
availability. And don't forget to backup regularly.

Good luck with your project and regards,
DuskoS

 

Dusko,

Thank you for the feedback and information. I intend to continue with the
single partition configuration.

-Caryn

"Dusko Savatovic" wrote:

> In line...
> "Caryn Condon" <CarynCondon@discussions.microsoft.com> wrote in message
> news:B62FBC22-544C-4CB8-A779-91BD134E6FC1@microsoft.com...
> > We have two Dell PE1950's with mirrored 73gb drives and 2gb of memory. We
> > need guidance for configuring the disk drives. These two servers will be
> > our
> > AD domain controllers and will also have integrated DNS.
> >
> > My questions are as follows:
> > 1. I read that it is recommended to store the AD database and logs on a
> > separate disk from the OS. Since I don't have the luxury of two separate
> > disks, is it ok to create on large partition for the OS, db and logs or
> > should I create two separate partitions?
>
> AD is organized and works as a database, hence the recommendation.
> However, AD is not such a large database as Exchange for example.
> It is safe to keep AD database and log on the OS volume.
>
> >
> > 2. I have already used these servers (using one large partition for the
> > os,
> > db and logs) for testing my upgrade path from NT4 to Win2k3 AD. During the
> > tests I noticed the following error on both servers:
> > "Event ID 1539
>
> <snip>
>
> Due to the way the databases work http://en.wikipedia.org/wiki/ACID , the OS
> will try to disable write cache to avoid database inconsistencies if a
> sudden break occurs in the middle of transaction.
>
> If your RAID controller has a battery backup, it is usually safe to leave
> write cache enabled on the disk.
>
> > Doing google searches I believe this error is because the db and log files
> > are on the same partition as the OS. I also came across notes on disabling
> > write cache but it is still unclear to me what my best option is. Should I
> > leave the write cache enabled or should I disable it on the RAID
> > controller?
> > I looked at the Dell Open Manage logs for the hardware and the RAID
> > controllery battery is fine and there are no raid or hard drive errors.
> >
> > Thanks in advance for any assistance.
>
> AD is rather robust and now a mature and well known technology. If you have
> two DC's in your domain and good, regular, trouble free replication between
> them, your domain will have a high level of fault tolerance and
> availability. And don't forget to backup regularly.
>
> Good luck with your project and regards,
> DuskoS
>
>

 

Hello Caryn,
YOu can configure your hardware into 2 RAID 1 arrays. Yes, it is a good idea
not to have AD database in same drive as OS.. In my environment, I have OS
in C and AD database (sysvol) in D drive.

--
Isaac Oben [MCTIP:EA, MCSE]
"Caryn Condon" <CarynCondon@discussions.microsoft.com> wrote in message
news:B62FBC22-544C-4CB8-A779-91BD134E6FC1@microsoft.com...
> We have two Dell PE1950's with mirrored 73gb drives and 2gb of memory. We
> need guidance for configuring the disk drives. These two servers will be
> our
> AD domain controllers and will also have integrated DNS.
>
> My questions are as follows:
> 1. I read that it is recommended to store the AD database and logs on a
> separate disk from the OS. Since I don't have the luxury of two separate
> disks, is it ok to create on large partition for the OS, db and logs or
> should I create two separate partitions?
>
> 2. I have already used these servers (using one large partition for the
> os,
> db and logs) for testing my upgrade path from NT4 to Win2k3 AD. During the
> tests I noticed the following error on both servers:
> "Event ID 1539
>
> The local domain controller could not disable the software-based disk
> write
> cache on the following hard disk.
>
> Hard Disk:
>
> C
>
> Data might be lost during system failures."
>
> Doing google searches I believe this error is because the db and log files
> are on the same partition as the OS. I also came across notes on disabling
> write cache but it is still unclear to me what my best option is. Should I
> leave the write cache enabled or should I disable it on the RAID
> controller?
> I looked at the Dell Open Manage logs for the hardware and the RAID
> controllery battery is fine and there are no raid or hard drive errors.
>
> Thanks in advance for any assistance.