RAID 1 OS / RAID 5 Data: Same or separate arrays?

[Josh Dunbar]

Hello,

How do I need configure RAID 1 for the OS and RAID 5 for my data? I thought I set it up correctly before, but after deploying the OS and going to Disk Management, I don't see my RAID 5 array. It just shows as unallocated space. I have 5 disks total in this server. 2 are RAID 1 (OS); the other 3 are RAID 5 in a separate array. Do I need to configure these two RAID types in the same array or separate arrays? I did them separately, but something is amiss if I can't see my RAID 5 volume in Windows. Please advise a solution. Thanks!

[Josh Dunbar]

Wanted to add a few more comments:

I configured both of the arrays at the same time using the SmartStart disc. The first two discs are RAID 1, the remaining three are RAID 5. I configured these on separate arrays. If this is not the correct way to setup this configuration, please comment below.

P.S.: Can you edit your own forum posts?

Thanks,

Josh Dunbar

[Michael A. McKenney]

Two arrays. RAID 1 or 10 for OS. I would do RAID 10 for data, the write performance is faster and you lose 5% on read performance over RAID 5. RAID 10 will require 4 disks. You might also want to place your paging/swap file in its own RAID 10 array. You can expand/shrink partitions in Windows 2008 that don't have a paging/swap file. It will also keep your OS from fighting for r/w with paging/swap.

[Josh Dunbar]

Michael,

Thank you for your reply.

I only have 5 drives total, so RAID 1 & 10 together is out. Also, I need to know why my RAID 5 array is showing as unallocated space in Disk Management. The only options I get when clicking on that unallocated space are "New Simple/Striped/Mirrored Volume", & properties. RAID 5 is grayed out. It does not show a drive letter, either. Do I need to format the RAID 5 array from SmartStart or BIOS to make this work?

Regards,



Josh Dunbar

[Michael A. McKenney]

You did hardware RAID 5 on a controller. You are not doing software RAID in Windows so you don't get RAID setup. So just create your extended/logical drives. I don't use primary for non-OS partitions.

You never want to put hardware RAID and software RAID together.

You should see your RAID 5 unallocated partition, it would be 2/3 total of the three drives.

[Ali]

Hi Josh,

Keeping the Raid 1 and Raid 5 in different arrays is the correct way of doing it.

As you mentioned both the volume were configured at the same time, so I am assuming you don't have anything to loose in Raid 5

let me clarify the Raid setup here: H/w Raid configured on the smart array controller does not do partitioning Infact OS reads the H/w Raid volume as a single physical disk.

So, you need to allocate space in new partition, assign a drive letter and format them in order to use the space for data.

Before doing that, I would suggest you to verify your Raid configuration in HP ACU utility and make sure there isn't any expand/extend operation is running and you have healthy and two seperate logical volume.

You May refer to ACU guide for raid configuratiion
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00729544/c00729544.pdf

hope this helps,

thanks,
Aftab

[gregersenj]

Josh, as I read your post and replies, you have done most things correctly.

You have createt a RAID 1 for the os, and installed the OS.
You have createt a RAID 5.
Windows show the RAID 5 as unallocatet space!.
All you need to do is format it in Windows.

Open disk manager.
Right clik
Choose what volume type you want. Do read the windows manual !!
Just go ahead and try if you have doubts. Foa sa long as the server is not in produktion, and no data is at risk. Now is the time to play with.

BR
/jag

[gregersenj]

http://technet.microsoft.com/en-us/library/cc754936.aspx

Try to follow the add new disk links.

And as mentioned by the other helpers.
Your RAID 5, do appear as a physical single disk.

BR
/jag

[Josh Dunbar]

Gregersenj,

I am not able to format the volume from Disk Management. The option does not appear. Not even as grayed out. The only options I have available with the RAID 5 unallocated space are: New Striped/Spanned/Mirrored Volume. Format is not listed there. Would Diskpart work from the command prompt?

By the way, this server is a domain controller. I meant to mention that in an earlier post. I was told RAID 1 + RAID 5 would be the best setup for a DC build. Please correct me if I am wrong.

Thank you,



Josh Dunbar

[Ali]

Hi Josh,

I overlooked this info
" The only options I have available with the RAID 5 unallocated space are: New Striped/Spanned/Mirrored Volume"

Windows reads h/w raid as basic disk. however gives you an option to also convert it to dynamic disk... this means software raid over h/w raid which is not suggested.

I guess, something wrong here as it's not allowing to assign a drive letter to unallocated space.
What is the server and Controller model?

Verify your Raid 5 volume from ACU and use windows Setup to create partition on raid 5 volume and format them. exit windows setup without continuing the install process.

Another option that you can consider is to remove array and raid 5 volume and re-create them.

By the way, this server is a domain controller. I meant to mention that in an earlier post. I was told RAID 1 + RAID 5 would be the best setup for a DC build. Please correct me if I am wrong.

Raid 1 is the ideal raid level for Operating system as it gives better fault tolerance and read/write performance than raid 5. So you are right saying that!

Thanks
Aftab