Solved

RAID 0 on an HP ML110 G6

Posted on 2011-03-18
14
2,222 Views
Last Modified: 2012-05-11
My ML110 G6 server boots Windows Server 2008 R2 from the 250Gb SATA drive that shipped with the unit. I've added another two 2Tb SATA drives. Enabling RAID on the BIOS allows me to press F8 during POST and to configure the two extra drives as a single RAID 0 disk.

However, when the server reboots, the original bootable drive is not recognised and the server tries to PXE boot.

How do I have te server boot from the original (non-RAID) disk, yet recognise the other two drives as a RAID 0?
0
Comment
Question by:nonaeos
  • 5
  • 4
  • 2
  • +2
14 Comments
 
LVL 7

Expert Comment

by:TheTull
Comment Utility
Quick question - You didn't inadvertently set the RAID 0 array to be the first and perhaps only boot device as far as "hard disks" go within the BIOS settings did you?  Meaning, is the original hard drive set as the first boot device (or first hard drive) in the boot device priority order?
0
 
LVL 47

Expert Comment

by:dlethe
Comment Utility
When you convert to RAID0, you lost everything.  Not only that, but there is a 2.09 TB limit for the size of the "C" disk.
Sorry
0
 
LVL 47

Expert Comment

by:dlethe
Comment Utility
There isn't a way to easily "undo" the damage, but it can be done by a pro.  (I am assuming you converted the 2TB "C" disk into a 6GB array so the RAID controller only sees 1 device that you partitioned in the controller to separate C and a 4TB D.  If you did something else, please elaborate in depth.  

DONT do a mbrfix or anything like that, you will likely make it much more expensive to recover.
0
 
LVL 7

Expert Comment

by:TheTull
Comment Utility
dlethe - It is my understanding that nonaeos "added" two extra drives and didn't touch the original boot drive.
0
 
LVL 4

Expert Comment

by:rjpilcher
Comment Utility
From your description, it sounds like you added the 2 TB drives as a data drive.  With the OS residing on the 256GB, you should be ok.  Have you tried removing the striped disks and booting?  

In the RAID manager can you see 2 virtual disks?  1 being the 256GB drive and the other being the 2TB drives?

Also, if you're going to do RAID 0, you need to make sure you format the disk as GPT instead of MBR so that the OS recognizes all the space (assuming you were making 1 large partition).  MBR has a limit of 2TB.  

The OS must be installed on an MBR partition, htough, as dlethe mentioned.
0
 

Author Comment

by:nonaeos
Comment Utility
My original 'bootable' disk is fully intact. If I disable RAID on the BIOS, then the Windows 2008 server boots up as before. So, I've lost nothing. I just can't seem to configure the new drives as RAID 0 whilst keeping the original drive as the bootable device.

When the BIOS is configured to 'RAID' setting, and pressing F8 during POST, I see the original disk as well as the two new disks. However, once the RAID 0 config is saved and a reboot carried out via iLO, the server does not boot from the original disk.
0
 

Author Comment

by:nonaeos
Comment Utility
In the RAID manager, I initially saw all three physical disks. However, after selecting that I want to create a single RAID 0 on the two 'new' disks, subsequent entry to the RAID manager (via F8 at POST) does not show the original bootable drive, but does show a single 4Tb RAID 0 drive.

0
What Is Threat Intelligence?

Threat intelligence is often discussed, but rarely understood. Starting with a precise definition, along with clear business goals, is essential.

 
LVL 47

Expert Comment

by:dlethe
Comment Utility
it is not possible to do this w/o a full backup & restore using some raid-aware software like ghost or acronics.   (And I am happy that I did misinterpret what you did).

The reason you just can't do this, is because in RAID mode, the number of usable blocks shrinks slightly, so there is not enough room to store the entire logical device.   Also, RAID0??  Really?
Sorry I will be a little politically incorrect ... you are making a grave mistake.  All it takes is one bad block on EITHER disk and you have irrecoverable data loss.  It would be really bad if the block was in the middle of an important database.

* You decrease reliability & availability by 50%.
* Performance will suffer in all but large block sequential writes.   This is not the norm for a server.  If you want overall speed, RAID1 will be better as you will be using random I/O, and little large block sequential.  RAID0 is better for video streaming.

Go RAID1, then next improvement will usually be RAID10, but 2 x RAID1s could be better for you then 1 x RAID10, it is a function of your specific needs.

RAID1 protects against not only a disk failure, but a single block failure.  get a bad block on RAID0, you lose data.  Get a bad block on RAID1, you might see a one particular I/O take a second or two longer.   Lose a disk in RAID0, you lose EVERYTHING.  

What is your data & time worth?  Surely more than the cost of getting the right disk config?
0
 

Author Comment

by:nonaeos
Comment Utility
Additionally, with 'RAID' enabled on the BIOS, when I try to specify the boot order in the BIOS ... the only option on the list of Hard Drives is to select the RAID Array. The original (bootable) HDD just doesn't seem to appear.
0
 
LVL 4

Expert Comment

by:needleboy
Comment Utility
HI nonaeos,

Do you have option in Raid Manager (F8) to mark drives as bootable?
This option add * caracter to logical drive.
0
 
LVL 4

Accepted Solution

by:
rjpilcher earned 250 total points
Comment Utility
It sounds like the BIOS is only looking for RAID volumes once you enable RAID. So your single disk isn't going to appear as a logical volume.  

I don't know if you can accomplish what you are trying to do without either rebuilding the server completely (perhaps with another 256GB disk to make an OS RAID 1) or use the 2x2TB to create either a RAID 1 or RAID 0 and rebuild the OS on that.
0
 
LVL 47

Expert Comment

by:dlethe
Comment Utility
"Additionally, with 'RAID' enabled on the BIOS, "
 Right .. this is an either-or situation.  Feel lucky that when you don't enable RAID it didn't blow away the first few MB of your disk drive like some other controllers do.
0
 

Author Comment

by:nonaeos
Comment Utility
I'm aware of the benefits and drawbacks of RAID 0. My backup regime is good. I simply want to boot this server from the original disk and add the two extra drives as a RAID 0 array. It's looking like this might not be possible.
0
 

Author Closing Comment

by:nonaeos
Comment Utility
It seems that once RAID option is enabled in the BIOS, any drives not configured via the 'F8' RAID manager are not visible to the server.
0

Featured Post

Zoho SalesIQ

Hassle-free live chat software re-imagined for business growth. 2 users, always free.

Join & Write a Comment

Suggested Solutions

Usually shares are where we want them for our users and we tend to take them for granted. There are times, however, when those shares may disappear causing difficulty for your users. One of the first things to try is searching for files that shou…
Learn about cloud computing and its benefits for small business owners.
This video discusses moving either the default database or any database to a new volume.
Polish reports in Access so they look terrific. Take yourself to another level. Equations, Back Color, Alternate Back Color. Write easy VBA Code. Tighten space to use less pages. Launch report from a menu, considering criteria only when it is filled…

762 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

13 Experts available now in Live!

Get 1:1 Help Now