Disk Mangement Advice

Greetings,
I have 6 x 9.1GB Dual channel Wide Ultra 2 SCSI Hot Swap Drives to setup
Windows 2000 Server on with only 2 applications which are Symantec
Antivirus and Peachtree Account Software. I plan to use Terminal Services
for mulit user access (just 3 users). How do I go about creating a RAID-1
"mirrored Volume" for the OS. It only allows me to create a RAID-1 with the
unallocated volume space,but not the existing volume with the OS . Is there
a way for me to properly install the OS and applications in a mirrored
environment? Also, would you recommend me creating a RAID-5 on the other 3
remaining Hard drives for just data and keeping 1 extra as a spare for fault
tolerance? Appreciate any feedback . Humbly grateful.

Joey

Use hardware RAID all the way around whenever possible. The operating
system should always be RAID-1 and the data on RAID-5. If possible, put the
volumes on separate SCSI channels so they can each have fully dedicated SCSI
bus speeds. Use two disks in RAID-1 for the OS. Use three disks in RAID-5
for the data. Keep the last disk available as a hot spare for the data
array.

Whenever you are using hardware RAID, keep your disks set to basic type if
you don't have specific needs for dynamic disks. See this MS Knowledge Base
article for further information:

http://support.microsoft.com/?id=816307

When using software RAID, you have to use dynamic disks, but do not use
dynamic disks for your OS drives, keep those set to basic.

--
Todd J Heron, MCSE
Windows Server 2003/2000/NT
----------------------------------------------------------------------------
This posting is provided "as is" with no warranties and confers no rights

"Joe" <jbcandullo(nospam)@mmadisonservices.com> wrote in message
news:%(E-Mail Removed)...
> Greetings,
> I have 6 x 9.1GB Dual channel Wide Ultra 2 SCSI Hot Swap Drives to setup
> Windows 2000 Server on with only 2 applications which are Symantec
> Antivirus and Peachtree Account Software. I plan to use Terminal Services
> for mulit user access (just 3 users). How do I go about creating a RAID-1
> "mirrored Volume" for the OS. It only allows me to create a RAID-1 with
> the unallocated volume space,but not the existing volume with the OS . Is
> there a way for me to properly install the OS and applications in a
> mirrored environment? Also, would you recommend me creating a RAID-5 on
> the other 3 remaining Hard drives for just data and keeping 1 extra as a
> spare for fault tolerance? Appreciate any feedback . Humbly grateful.
>
> Joey

If you are using hardware RAID, then use five of the drives in a RAID5 and
the sixth as a spare.

If you are using software RAID, you can't boot from RAID5 so there I would
suggest using a mirrored RAID1 for the system and the remaining four drives
as a RAID5. I don't think you can have a spare in a software RAID. RAID5
offers redundancy and striping for speed gains plus better utilization of
the space so is generally better then mirrored drives - with the exception
of not being able to boot from a software RAID5.

Using Disk Management, you can convert the system drive to a dynamic volume
and then it will allow you to add a mirrored drive. While the Windows server
will allow you to do this, it's not recomended in some cases.

http://www.microsoft.com/windows2000...iderations.htm

I have software RAID1 and RAID5 over four drives. I lost the ability to boot
from either of my software mirrored drives after doing a defrag. I think the
only way to fix the problem is to reformat as a basic disk, then convert to
a dynamic, etc. But don't let that scare you, the system drive should be at
least mirrored.

Understanding that there really is no wrong way to do things, I think that
this is a bad idea. Running your system drive on a RAID5 array isn't a great
option because it offers a slower Read time than a RAID1 array since in RAID1
you are reading from 1 disk and in RAID5 you are reading from 3+ drives.

The system drive should be on RAID1 and your data/app drives on a RAID5
array unless you really require performance on those drives when you can look
at some alternatives to RAID5, but you would really need a pretty hefty
application to have to start looking at that.

Phil

"m.marien" wrote:

>
> "Joe" <jbcandullo(nospam)@mmadisonservices.com> wrote in message
> news:%(E-Mail Removed)...
> > Greetings,
> > I have 6 x 9.1GB Dual channel Wide Ultra 2 SCSI Hot Swap Drives to setup
> > Windows 2000 Server on with only 2 applications which are Symantec
> > Antivirus and Peachtree Account Software. I plan to use Terminal Services
> > for mulit user access (just 3 users). How do I go about creating a RAID-1
> > "mirrored Volume" for the OS. It only allows me to create a RAID-1 with
> > the unallocated volume space,but not the existing volume with the OS . Is
> > there a way for me to properly install the OS and applications in a
> > mirrored environment? Also, would you recommend me creating a RAID-5 on
> > the other 3 remaining Hard drives for just data and keeping 1 extra as a
> > spare for fault tolerance? Appreciate any feedback . Humbly grateful.
> >
> > Joey
>
> If you are using hardware RAID, then use five of the drives in a RAID5 and
> the sixth as a spare.
>
> If you are using software RAID, you can't boot from RAID5 so there I would
> suggest using a mirrored RAID1 for the system and the remaining four drives
> as a RAID5. I don't think you can have a spare in a software RAID. RAID5
> offers redundancy and striping for speed gains plus better utilization of
> the space so is generally better then mirrored drives - with the exception
> of not being able to boot from a software RAID5.
>
> Using Disk Management, you can convert the system drive to a dynamic volume
> and then it will allow you to add a mirrored drive. While the Windows server
> will allow you to do this, it's not recomended in some cases.
>
> http://www.microsoft.com/windows2000...iderations.htm
>
> I have software RAID1 and RAID5 over four drives. I lost the ability to boot
> from either of my software mirrored drives after doing a defrag. I think the
> only way to fix the problem is to reformat as a basic disk, then convert to
> a dynamic, etc. But don't let that scare you, the system drive should be at
> least mirrored.
>
>
>

"Phillip Renouf" <(E-Mail Removed)> wrote in message
news:5DA17D2B-6E6D-4CD2-839F-(E-Mail Removed)...
> Understanding that there really is no wrong way to do things, I think that
> this is a bad idea. Running your system drive on a RAID5 array isn't a
> great
> option because it offers a slower Read time than a RAID1 array since in
> RAID1
> you are reading from 1 disk and in RAID5 you are reading from 3+ drives.
>

I think that is the whole idea. Reading from multiple drives in parallel
moves the data n-1 times faster where n is the number of drives in the
RAID5. It's n-1 because one of the drives just holds the parity.

http://www.pcguide.com/ref/hdd/perf/...eLevel5-c.html

You generally get better then RAID0 reading when you have more than three
drives.

RAID1 is the slowest read and write. It reads from one drive which isn't any
better then having a single drive and has to write the data twice. Once to
each drive. The only thing it offers is redundancy.

The only problem is that you can't boot from a software RAID5, whereas you
can from a software RAID1. With software RAID1 you are just reading from one
drive. If you have hardware RAID, then you can boot from any RAID level, as
the RAID looks like a single drive to the o/s.

"m.marien" <mm AT RiverCityCanada DOT com> wrote in message
news:(E-Mail Removed)...
> The only problem is that you can't boot from a software RAID5, whereas you
> can from a software RAID1.

Not the case. All our machines are RAID5 and they obviously boot up. We did
it with NT4, Server2000 and now Server2003. I have seen articles and
materials that made the same claims, even in the CISCO CCNA material,...but
the material is just wrong.

They may have been refering to Software RAID5 done using the OS itself, but
if that is the case they need to be more clear about it.

--

Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com

"Phillip Windell" <@.> wrote in message
news:evW3%(E-Mail Removed)...
> "m.marien" <mm AT RiverCityCanada DOT com> wrote in message
> news:(E-Mail Removed)...
>> The only problem is that you can't boot from a software RAID5, whereas
>> you
>> can from a software RAID1.
>
> Not the case. All our machines are RAID5 and they obviously boot up.

You have a Windows software RAID5 and can boot from it ? According to MS you
can't do that with a RAID5:

http://www.microsoft.com/windows2000...tware_raid.htm

I guess the question I would have is, do you create the software RAID5
before you install the o/s? or how does that work?

"m.marien" <mm AT RiverCityCanada DOT com> wrote in message
news:(E-Mail Removed)...
> > Not the case. All our machines are RAID5 and they obviously boot up.
>
> You have a Windows software RAID5 and can boot from it ? According to MS
you
> can't do that with a RAID5:

No,..I said I have RAID5, I didn't say anything about Windows RAID which is
software RAID. My last post said:

"They may have been refering to Software RAID5 done using the OS itself, but
if that is the case they need to be more clear about it."

Todd clearly indicated in his post to use Hardware RAID, which I agree, and
consider it to be the only RAID really worth bothering with, and is the only
kind I run here.

I looked as far back in the original post as I could and it was never clear
(at least in the messages I have) if it was Hardware or Software RAID.
The training materials I refered to ealier didn't indicate which type they
were refering to either,...which a big oversight on their part when it is
material to train those who don't know any better.

--

Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com

I got that backwards, my appology: that'll teach me to make posts right after
coming back from vacation

Writing to a RAID5 set is a much bigger performance hit than writing to a
RAID1 set. In a RAID1 set you are only writing to 2 drives, but in a RAID5
set you are writing to 3+ drives and it also has to calculate the parity
information.

Also, the n-1 does not denote that one drive holds the parity data:
effectively with a RAID5 set the available drive space is effectively equal
to n-1. The parity data is actually spread across all the drives.

Phil

"m.marien" wrote:

>
> "Phillip Renouf" <(E-Mail Removed)> wrote in message
> news:5DA17D2B-6E6D-4CD2-839F-(E-Mail Removed)...
> > Understanding that there really is no wrong way to do things, I think that
> > this is a bad idea. Running your system drive on a RAID5 array isn't a
> > great
> > option because it offers a slower Read time than a RAID1 array since in
> > RAID1
> > you are reading from 1 disk and in RAID5 you are reading from 3+ drives.
> >
>
> I think that is the whole idea. Reading from multiple drives in parallel
> moves the data n-1 times faster where n is the number of drives in the
> RAID5. It's n-1 because one of the drives just holds the parity.
>
> http://www.pcguide.com/ref/hdd/perf/...eLevel5-c.html
>
> You generally get better then RAID0 reading when you have more than three
> drives.
>
> RAID1 is the slowest read and write. It reads from one drive which isn't any
> better then having a single drive and has to write the data twice. Once to
> each drive. The only thing it offers is redundancy.
>
> The only problem is that you can't boot from a software RAID5, whereas you
> can from a software RAID1. With software RAID1 you are just reading from one
> drive. If you have hardware RAID, then you can boot from any RAID level, as
> the RAID looks like a single drive to the o/s.
>
>
>
>

"Phillip Renouf" <(E-Mail Removed)> wrote in message
news:2DD332DE-C485-496F-A186-(E-Mail Removed)...
> Writing to a RAID5 set is a much bigger performance hit than writing to a
> RAID1 set. In a RAID1 set you are only writing to 2 drives, but in a RAID5
> set you are writing to 3+ drives and it also has to calculate the parity
> information.
>
> Also, the n-1 does not denote that one drive holds the parity data:
> effectively with a RAID5 set the available drive space is effectively
equal
> to n-1. The parity data is actually spread across all the drives.

No, the fact that it is 3 drives (or 4 or 5) doesn't not make it slower. In
fact it is faster because it writes to all of them at same time and does not
have to write the data twice. The data is also evenly divided across the
drives so that only a portion of the data need to be writen to each one.
There is a slight time loss for the Parity but the "cost" of this negligable
and often exaggerated and is nearly compensated for by the faster
writetimes. There is also two RAID5's,...there is RAID5 with Parity and
Raid5 without Parity (Stripped Set). The RAID5 without Parity is the fastest
RAID of them all.

RAID1 is slower because and entire copy of the data goes to the second drive
so the data being completely written twice in its entirety creates a "cost".

--

Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com