Building New Server - What RAID should be used and how to divide the files
among the disk drives?

Ok. I admit I am completely confused. I am being asked to research for a
new server. My manager wants to know how many drives are needed depending on
the RAID. Currently our organization is using RAID-5. However, I am not
sure how to split up the data files and transactional logs.

Should the master, msdb, model data files be on drive e?
Should the master, msdb, model log files be on drive g?
Or should each database data file be on its own drive and each database log
file on another drive?
Or should all the data files be on one drive and the log files on a second
drive?
What about tempdb? Should the tempdb data file be on one drive separate
from the others and its log file on a drive separate from the other log
files? Also I think that I read that tempdb should be on RAID 0; that it can
be on a separate RAID from the other files? Is this true?

This is an example that I have put together. I don't know how correct/not
correct it is though.
c: operating system ?
d: data files for all user databases ?
e: data files for all system databases ?
f: log files for all user databases ?
g: log files for all system databases ?
h: tempdb data file RAID 0
i: tempdb log file RAID 0

He made a remark that he thought that we might need about 16 drives? I am
not sure I understand the relationship between the drives and RAID. I am
wondering if I am misunderstanding him.

How do most people have their servers set up?

Are there recommendations which files should be what RAID?

I hate to say that but "it depends...".

It depends how often heavily your servers are being used. What your needs
are and the workload on them etc.

If you are asking for the best practices, Operating System and SQL Server
are setup on the same RAID which is RAID1 which will provide you performance
+ redundancy.

System files would not be used frequently (tempdb is an exception and it is
being used more in SQL Server 2005). You can keep them on C: if their sizes
would not grow in huge amounts. I don't know your plans but if tempdb is
going to be used frequently in your environment, then you can keep it on a
RAID0. Which is gonna provide the fastest write performance but without
redundancy, consider this. However, tempdb is going to be used temporarily
so people do not look for redundancy for tempdb. You do not need to seperate
system databases' mdf and ldf files. However, you should backup them when
you make changes in your SQL Server (like creating jobs, configuring linked
servers, creating logins, attaching\detaching databases etc.)

You can keep the log files and data files of your user databases at
different RAIDs. RAID1 would be good for T-Log files and RAID10 (better) or
RAID5 would be OK for *.mdf files.

According to the list below, I could say:
> c: operating system RAID1
> d: data files for all user databases RAID10 \ RAID5
> f: log files for all user databases RAID1
> h: tempdb RAID 0

If you have more than one database (or if you want to devide your VLDB if
there is any) then you could consider locating them to another RAIDs to gain
more performance.

I just tried to tell you the best practices as far as I know. This does not
mean they are just for you and fit to your environment. My purpose is just
to shed a light for you.

I believe my friends will correct me if there is something wrong with my
suggestions.

--
Ekrem Önsoy



"lcerni" <lcerni@discussions.microsoft.com> wrote in message
news:A36B636F-D433-40E6-8EF6-B70AFB929907@microsoft.com...
> Building New Server - What RAID should be used and how to divide the files
> among the disk drives?
>
> Ok. I admit I am completely confused. I am being asked to research for a
> new server. My manager wants to know how many drives are needed depending
> on
> the RAID. Currently our organization is using RAID-5. However, I am not
> sure how to split up the data files and transactional logs.
>
> Should the master, msdb, model data files be on drive e?
> Should the master, msdb, model log files be on drive g?
> Or should each database data file be on its own drive and each database
> log
> file on another drive?
> Or should all the data files be on one drive and the log files on a second
> drive?
> What about tempdb? Should the tempdb data file be on one drive separate
> from the others and its log file on a drive separate from the other log
> files? Also I think that I read that tempdb should be on RAID 0; that it
> can
> be on a separate RAID from the other files? Is this true?
>
> This is an example that I have put together. I don't know how correct/not
> correct it is though.
> c: operating system ?
> d: data files for all user databases ?
> e: data files for all system databases ?
> f: log files for all user databases ?
> g: log files for all system databases ?
> h: tempdb data file RAID 0
> i: tempdb log file RAID 0
>
> He made a remark that he thought that we might need about 16 drives? I am
> not sure I understand the relationship between the drives and RAID. I am
> wondering if I am misunderstanding him.
>
> How do most people have their servers set up?
>
> Are there recommendations which files should be what RAID?
>

I shared this information with my manager and he informed me that he wants me
to write a Word Document like a proposal. Is there a template out there that
I can look at? I am not sure how to go about writing this up. How the
format should be? etc.

"Ekrem Önsoy" wrote:

> I hate to say that but "it depends...".
>
> It depends how often heavily your servers are being used. What your needs
> are and the workload on them etc.
>
> If you are asking for the best practices, Operating System and SQL Server
> are setup on the same RAID which is RAID1 which will provide you performance
> + redundancy.
>
> System files would not be used frequently (tempdb is an exception and it is
> being used more in SQL Server 2005). You can keep them on C: if their sizes
> would not grow in huge amounts. I don't know your plans but if tempdb is
> going to be used frequently in your environment, then you can keep it on a
> RAID0. Which is gonna provide the fastest write performance but without
> redundancy, consider this. However, tempdb is going to be used temporarily
> so people do not look for redundancy for tempdb. You do not need to seperate
> system databases' mdf and ldf files. However, you should backup them when
> you make changes in your SQL Server (like creating jobs, configuring linked
> servers, creating logins, attaching\detaching databases etc.)
>
> You can keep the log files and data files of your user databases at
> different RAIDs. RAID1 would be good for T-Log files and RAID10 (better) or
> RAID5 would be OK for *.mdf files.
>
> According to the list below, I could say:
> > c: operating system RAID1
> > d: data files for all user databases RAID10 \ RAID5
> > f: log files for all user databases RAID1
> > h: tempdb RAID 0
>
> If you have more than one database (or if you want to devide your VLDB if
> there is any) then you could consider locating them to another RAIDs to gain
> more performance.
>
> I just tried to tell you the best practices as far as I know. This does not
> mean they are just for you and fit to your environment. My purpose is just
> to shed a light for you.
>
> I believe my friends will correct me if there is something wrong with my
> suggestions.
>
> --
> Ekrem Önsoy
>
>
>
> "lcerni" <lcerni@discussions.microsoft.com> wrote in message
> news:A36B636F-D433-40E6-8EF6-B70AFB929907@microsoft.com...
> > Building New Server - What RAID should be used and how to divide the files
> > among the disk drives?
> >
> > Ok. I admit I am completely confused. I am being asked to research for a
> > new server. My manager wants to know how many drives are needed depending
> > on
> > the RAID. Currently our organization is using RAID-5. However, I am not
> > sure how to split up the data files and transactional logs.
> >
> > Should the master, msdb, model data files be on drive e?
> > Should the master, msdb, model log files be on drive g?
> > Or should each database data file be on its own drive and each database
> > log
> > file on another drive?
> > Or should all the data files be on one drive and the log files on a second
> > drive?
> > What about tempdb? Should the tempdb data file be on one drive separate
> > from the others and its log file on a drive separate from the other log
> > files? Also I think that I read that tempdb should be on RAID 0; that it
> > can
> > be on a separate RAID from the other files? Is this true?
> >
> > This is an example that I have put together. I don't know how correct/not
> > correct it is though.
> > c: operating system ?
> > d: data files for all user databases ?
> > e: data files for all system databases ?
> > f: log files for all user databases ?
> > g: log files for all system databases ?
> > h: tempdb data file RAID 0
> > i: tempdb log file RAID 0
> >
> > He made a remark that he thought that we might need about 16 drives? I am
> > not sure I understand the relationship between the drives and RAID. I am
> > wondering if I am misunderstanding him.
> >
> > How do most people have their servers set up?
> >
> > Are there recommendations which files should be what RAID?
> >
>

Don't take this the wrong way but why is he asking you to come up with
something that you admit you know nothing about? There are a lot of factors
to consider and we don't have enough information to give you the best answer
for your situation. He should contract someone who does know how to get to
the bottom of this so that you make the correct decision and do it right the
first time. But some basics are:

Don't confuse a Logical drive with a Physical drive or array. Creating
multiple Logical drives such as C:, D: & E: on one physical array does
nothing for performance but gives false impressions of files residing on
different drives.

Never use Raid 0 if you are concerned with data loss.

Raid 5 should only be considered if there is mostly Read activity or very
low write activity. Raid 10 is a better choice for data files.

RAID 1 is a starting point for Log files. Heavy systems may need Raid 10

Never mix Log files with Data files. You can get away with adding multiple
log files to a single Raid 1 but never put data files on it.

Use a Raid 1 for the OS and sql binaries. If the usage is low enough you can
usually get by with placing the log files on this array as well.
--
Andrew J. Kelly SQL MVP
Solid Quality Mentors


"lcerni" <lcerni@discussions.microsoft.com> wrote in message
news:A36B636F-D433-40E6-8EF6-B70AFB929907@microsoft.com...
> Building New Server - What RAID should be used and how to divide the files
> among the disk drives?
>
> Ok. I admit I am completely confused. I am being asked to research for a
> new server. My manager wants to know how many drives are needed depending
> on
> the RAID. Currently our organization is using RAID-5. However, I am not
> sure how to split up the data files and transactional logs.
>
> Should the master, msdb, model data files be on drive e?
> Should the master, msdb, model log files be on drive g?
> Or should each database data file be on its own drive and each database
> log
> file on another drive?
> Or should all the data files be on one drive and the log files on a second
> drive?
> What about tempdb? Should the tempdb data file be on one drive separate
> from the others and its log file on a drive separate from the other log
> files? Also I think that I read that tempdb should be on RAID 0; that it
> can
> be on a separate RAID from the other files? Is this true?
>
> This is an example that I have put together. I don't know how correct/not
> correct it is though.
> c: operating system ?
> d: data files for all user databases ?
> e: data files for all system databases ?
> f: log files for all user databases ?
> g: log files for all system databases ?
> h: tempdb data file RAID 0
> i: tempdb log file RAID 0
>
> He made a remark that he thought that we might need about 16 drives? I am
> not sure I understand the relationship between the drives and RAID. I am
> wondering if I am misunderstanding him.
>
> How do most people have their servers set up?
>
> Are there recommendations which files should be what RAID?
>

I agree with Andrew from the start to the end of his message.

He also told you some from Best Practices, however, best practices may not
apply your environment. We do not even know if your databases is OLAP or
OLTP, I think it would be right to say "You should determine this first of
all"

--
Ekrem Önsoy



"Andrew J. Kelly" <sqlmvpnooospam@shadhawk.com> wrote in message
news:%23a6X1rsCIHA.1188@TK2MSFTNGP04.phx.gbl...
> Don't take this the wrong way but why is he asking you to come up with
> something that you admit you know nothing about? There are a lot of
> factors to consider and we don't have enough information to give you the
> best answer for your situation. He should contract someone who does know
> how to get to the bottom of this so that you make the correct decision and
> do it right the first time. But some basics are:
>
> Don't confuse a Logical drive with a Physical drive or array. Creating
> multiple Logical drives such as C:, D: & E: on one physical array does
> nothing for performance but gives false impressions of files residing on
> different drives.
>
> Never use Raid 0 if you are concerned with data loss.
>
> Raid 5 should only be considered if there is mostly Read activity or very
> low write activity. Raid 10 is a better choice for data files.
>
> RAID 1 is a starting point for Log files. Heavy systems may need Raid 10
>
> Never mix Log files with Data files. You can get away with adding multiple
> log files to a single Raid 1 but never put data files on it.
>
> Use a Raid 1 for the OS and sql binaries. If the usage is low enough you
> can usually get by with placing the log files on this array as well.
> --
> Andrew J. Kelly SQL MVP
> Solid Quality Mentors
>
>
> "lcerni" <lcerni@discussions.microsoft.com> wrote in message
> news:A36B636F-D433-40E6-8EF6-B70AFB929907@microsoft.com...
>> Building New Server - What RAID should be used and how to divide the
>> files
>> among the disk drives?
>>
>> Ok. I admit I am completely confused. I am being asked to research for
>> a
>> new server. My manager wants to know how many drives are needed
>> depending on
>> the RAID. Currently our organization is using RAID-5. However, I am not
>> sure how to split up the data files and transactional logs.
>>
>> Should the master, msdb, model data files be on drive e?
>> Should the master, msdb, model log files be on drive g?
>> Or should each database data file be on its own drive and each database
>> log
>> file on another drive?
>> Or should all the data files be on one drive and the log files on a
>> second
>> drive?
>> What about tempdb? Should the tempdb data file be on one drive separate
>> from the others and its log file on a drive separate from the other log
>> files? Also I think that I read that tempdb should be on RAID 0; that it
>> can
>> be on a separate RAID from the other files? Is this true?
>>
>> This is an example that I have put together. I don't know how
>> correct/not
>> correct it is though.
>> c: operating system ?
>> d: data files for all user databases ?
>> e: data files for all system databases ?
>> f: log files for all user databases ?
>> g: log files for all system databases ?
>> h: tempdb data file RAID 0
>> i: tempdb log file RAID 0
>>
>> He made a remark that he thought that we might need about 16 drives? I
>> am
>> not sure I understand the relationship between the drives and RAID. I am
>> wondering if I am misunderstanding him.
>>
>> How do most people have their servers set up?
>>
>> Are there recommendations which files should be what RAID?
>>
>

It is a transactional database that is also used for reporting. It also
doesn't have the best designed.

"Ekrem Önsoy" wrote:

> I agree with Andrew from the start to the end of his message.
>
> He also told you some from Best Practices, however, best practices may not
> apply your environment. We do not even know if your databases is OLAP or
> OLTP, I think it would be right to say "You should determine this first of
> all"
>
> --
> Ekrem Önsoy
>
>
>
> "Andrew J. Kelly" <sqlmvpnooospam@shadhawk.com> wrote in message
> news:%23a6X1rsCIHA.1188@TK2MSFTNGP04.phx.gbl...
> > Don't take this the wrong way but why is he asking you to come up with
> > something that you admit you know nothing about? There are a lot of
> > factors to consider and we don't have enough information to give you the
> > best answer for your situation. He should contract someone who does know
> > how to get to the bottom of this so that you make the correct decision and
> > do it right the first time. But some basics are:
> >
> > Don't confuse a Logical drive with a Physical drive or array. Creating
> > multiple Logical drives such as C:, D: & E: on one physical array does
> > nothing for performance but gives false impressions of files residing on
> > different drives.
> >
> > Never use Raid 0 if you are concerned with data loss.
> >
> > Raid 5 should only be considered if there is mostly Read activity or very
> > low write activity. Raid 10 is a better choice for data files.
> >
> > RAID 1 is a starting point for Log files. Heavy systems may need Raid 10
> >
> > Never mix Log files with Data files. You can get away with adding multiple
> > log files to a single Raid 1 but never put data files on it.
> >
> > Use a Raid 1 for the OS and sql binaries. If the usage is low enough you
> > can usually get by with placing the log files on this array as well.
> > --
> > Andrew J. Kelly SQL MVP
> > Solid Quality Mentors
> >
> >
> > "lcerni" <lcerni@discussions.microsoft.com> wrote in message
> > news:A36B636F-D433-40E6-8EF6-B70AFB929907@microsoft.com...
> >> Building New Server - What RAID should be used and how to divide the
> >> files
> >> among the disk drives?
> >>
> >> Ok. I admit I am completely confused. I am being asked to research for
> >> a
> >> new server. My manager wants to know how many drives are needed
> >> depending on
> >> the RAID. Currently our organization is using RAID-5. However, I am not
> >> sure how to split up the data files and transactional logs.
> >>
> >> Should the master, msdb, model data files be on drive e?
> >> Should the master, msdb, model log files be on drive g?
> >> Or should each database data file be on its own drive and each database
> >> log
> >> file on another drive?
> >> Or should all the data files be on one drive and the log files on a
> >> second
> >> drive?
> >> What about tempdb? Should the tempdb data file be on one drive separate
> >> from the others and its log file on a drive separate from the other log
> >> files? Also I think that I read that tempdb should be on RAID 0; that it
> >> can
> >> be on a separate RAID from the other files? Is this true?
> >>
> >> This is an example that I have put together. I don't know how
> >> correct/not
> >> correct it is though.
> >> c: operating system ?
> >> d: data files for all user databases ?
> >> e: data files for all system databases ?
> >> f: log files for all user databases ?
> >> g: log files for all system databases ?
> >> h: tempdb data file RAID 0
> >> i: tempdb log file RAID 0
> >>
> >> He made a remark that he thought that we might need about 16 drives? I
> >> am
> >> not sure I understand the relationship between the drives and RAID. I am
> >> wondering if I am misunderstanding him.
> >>
> >> How do most people have their servers set up?
> >>
> >> Are there recommendations which files should be what RAID?
> >>
> >
>

lcerni wrote:
> Building New Server - What RAID should be used and how to divide the files
> among the disk drives?
>
> Ok. I admit I am completely confused. I am being asked to research for a
> new server. My manager wants to know how many drives are needed depending on
> the RAID. Currently our organization is using RAID-5. However, I am not
> sure how to split up the data files and transactional logs.
>
> Should the master, msdb, model data files be on drive e?
> Should the master, msdb, model log files be on drive g?
> Or should each database data file be on its own drive and each database log
> file on another drive?
> Or should all the data files be on one drive and the log files on a second
> drive?
> What about tempdb? Should the tempdb data file be on one drive separate
> from the others and its log file on a drive separate from the other log
> files? Also I think that I read that tempdb should be on RAID 0; that it can
> be on a separate RAID from the other files? Is this true?
>
> This is an example that I have put together. I don't know how correct/not
> correct it is though.
> c: operating system ?
> d: data files for all user databases ?
> e: data files for all system databases ?
> f: log files for all user databases ?
> g: log files for all system databases ?
> h: tempdb data file RAID 0
> i: tempdb log file RAID 0
>
> He made a remark that he thought that we might need about 16 drives? I am
> not sure I understand the relationship between the drives and RAID. I am
> wondering if I am misunderstanding him.
>
> How do most people have their servers set up?
>
> Are there recommendations which files should be what RAID?
>
We are set up as:

C: Boot (RAID 1 - 2 drives)
D: SQL & Log files (RAID 1 - 2 drives)
E: Database files (RAID 10 - 4 drives)


--

Regards,
Hank Arnold
Microsoft MVP
Windows Server - Directory Services