Raid 5 Please help

[Wowgasm]

Hi there,

I hope this is under the right section.

I just bought a brand new HP ML350 G6 server with 4 1TB drives.

I've installed the drives with Windows 2008 std 32-bit with raid 5.
For some reason, The computer recognizes the 2.7 TB which is fine, but 700GB of that 2.7TB is unusable. I cannot partition it, I cannot access it, nothing nada. Is this normal? Or did I do something wrong when I set up the array?

I mailed HP but no reply yet and I'm desperate here.
Thanks alot in advanced

 

[nivek]

You need to create a smaller virtual drive, to use as a boot partition. Windows doesn't support drives larger than 2TB, unless they are GPT disks- only problem is Windows cant boot from a GPT disk.

You can create the 2 arrays from HP's easy setup DVD

 

[Wowgasm]

Thank you so much, I'm going to redo the array now. Will repost once I'm done. Thanks for the help.

 

[The_Unbeliever]

Included with the server is a QuickStart DVD - boot from it, you'll be able to create the array using this DVD.

Create a 100Gb for Windows, and the rest for data etc.

Been there, done that, got the T-shirt.

I prefer working with HP ProLiant servers as they're very easy to set up and maintain than other servers I've seen so far.

Best to do is to create both partitions on a RAID-5 array though, as this will protect both partitions from data loss.

Don't the ML350 G6 have RAID-6 support? The only difference between 5 and 6 is that 6 can handle two failed disks, but 5 can only handle one failed disk.

Good luck.

 

[Mike Hoxbig]

Hi there,

I hope this is under the right section.

I just bought a brand new HP ML350 G6 server with 4 1TB drives.

I've installed the drives with Windows 2008 std 32-bit with raid 5.
For some reason, The computer recognizes the 2.7 TB which is fine, but 700GB of that 2.7TB is unusable. I cannot partition it, I cannot access it, nothing nada. Is this normal? Or did I do something wrong when I set up the array?

I mailed HP but no reply yet and I'm desperate here.
Thanks alot in advanced

Seems about right, refer to http://en.wikipedia.org/wiki/RAID#Standard_levels

You space efficiency would be (1 - 1/n), where n is the number of drives. Since you have 4 drives, your space efficiency would be 0.75. So 0.75 * 4TB would give you 3TB of useable space.

Since you don't get exactly the amount of space quoted for drives anyway (for example a 1TB drive would give you ~900GB of free space straight out the box), 2.7TB of free space on a RAID5 array sounds about right.

 

[<?php?>]

. . . , but 700GB of that 2.7TB is unusable . . .

Congrats on the server choice. We are running a ML350 G6 as well, with RAID 1-0.

Isn’t the 700GB being allocated for parity?

NOTE: Update the Array Controller and HDD firmware on a regular basis, we had some HDD issues. Great machine though!

 

[Wowgasm]

Hehe I pushed for raid 6 but my boss insisted raid 5. He chose more space over better fault tolerance. Not my call I'm afraid

I've created two logical drives, a 2TB and a 780 +/- drive which I'll partition in a 100GB drive for windows and then the rest for data. So in effect, I'll have 3 drives. Which is kinna perfect for the setup we're using.

Thanks so much for the help

 

[Wowgasm]

Congrats on the server choice. We are running a ML350 G6 as well, with RAID 1-0.

Isn’t the 700GB being allocated for parity?

NOTE: Update the Array Controller and HDD firmware on a regular basis, we had some HDD issues. Great machine though!

I found out that its because I'm running 32-bit OS. It can only see 2 TB hence why I had to break up the drives and create 2 logical drives. It uses about 1.6 TB for parity (just fyi) I'll keep the updates in mind. The HP servers ain't all that bad. I'm a Dell fanboy, but can't really complain about HP ML350's

 

[Cruelty]

It has nothing to do with 32-bit OS and everything to do with this:

You need to create a smaller virtual drive, to use as a boot partition. Windows doesn't support drives larger than 2TB, unless they are GPT disks- only problem is Windows cant boot from a GPT disk.

You can create the 2 arrays from HP's easy setup DVD