Solved

RAID Management query

Posted on 2011-03-16
12
339 Views
Last Modified: 2016-12-08
I have a server with a raid controller and 7 disks.

Each disk is 500 GB in size.

I want RAID 1 with 2 disks for OS. RAID 5 with 5 disks for data.

Problem is RAID 1 on 500 GB for solely OS is a waste. Can I somehow allocate 450 GB of the OS RAID 1 to the RAID 5?

In the DELL setup utlility it seems I have to use the entire 2 disks. Can I somehow manage this after the OS is installed?

I would like to see OS RAID 1 50 GB, DATA RAID 5 2 TB

Regards
0
Comment
Question by:Network_Padawan
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 3
  • 3
  • +2
12 Comments
 
LVL 9

Expert Comment

by:pcchiu
ID: 35152899
You can't do that as the hard drive physically in 500G.    

You can get 2x120GB hard drive for the OS and then save the 500GB for the RAID10 which may serve your purpose?

0
 
LVL 76

Assisted Solution

by:Alan Hardisty
Alan Hardisty earned 25 total points
ID: 35152903
With 500gb drives using 5 for RAID 5, you will have 2TB of data anyway, but the short answer is that you can't allocate the 450gb of space on the RAID 1 volume to the RAID 5 volume.

I would stick to a 500gb C: drive and enjoy the space!
0
 
LVL 9

Expert Comment

by:pcchiu
ID: 35152904
I also suggest using RAID 10 instead of RAID 5 if possible.
http://www.cyberciti.biz/tips/raid5-vs-raid-10-safety-performance.html

0
Don't Miss ATEN at InfoComm 2017!

Visit booth #2167 to see the  new ATEN VM3200 32 x 32 Modular Matrix Switch. Other highlights include the VE8950 4K HDMI Over IP Extender, VS1912 12-Port DP Video Wall Media Player  and VK2100 ATEN Control System. Register now with Free Pass Code ATEN288!

 
LVL 33

Assisted Solution

by:PowerEdgeTech
PowerEdgeTech earned 70 total points
ID: 35152943
I too would recommend sticking with two drives for the OS - or getting two high-speed, smaller drives for the OS.

OR...

Your controller will also support multiple RAID 5's across the same set of disks, so you could create a RAID 5 of 50GB across all 7 disks, then use the remaining amount in another RAID 5.  This is called slicing.  This cannot be done in the Dell installation utility.  It must be set up in the CTRL-R configuration utility during POST, then skip that option during the installation utility (or skip the use of the utility altogether).  You would end up with a data "disk" in Windows that is larger than 2TB, so you would have to convert it to GPT before partitioning it.
0
 

Author Comment

by:Network_Padawan
ID: 35152952
Hi PowerEdge, I wasnt aware you could do slicing...will give that a try
0
 

Author Comment

by:Network_Padawan
ID: 35152990
pcchiu, why would i go for RAID 10? I stand to lose 500 GB with that setup
0
 
LVL 9

Assisted Solution

by:pcchiu
pcchiu earned 50 total points
ID: 35153065
I don't think you want to do slicing as if anything went wrong you may not able to recover any data, as RAID1 is the simplest raid and you can recover data and repair it easily.  With slicing in case anything went wrong it's make it much harder for recovery.

RAID 10 you gain on performance...  So if performance is more of the concern you may want to go for it, if the storage size is more important you can stick with RAID5..

0
 
LVL 33

Expert Comment

by:PowerEdgeTech
ID: 35153079
If you are using a Dell controller that will do RAID 5, it will also support slicing.

Which system/RAID controller are you using?

RAID 10 vs RAID 5 generally has better write performance (common for databases), and gives you "up to" two-drive fault tolerance (you can lose up to 2 drives and still have access to the data).  It does come at a disk/space cost though.
0
 
LVL 33

Expert Comment

by:PowerEdgeTech
ID: 35153127
Which is why I still recommend using two drives dedicated to the OS, but the controller can do it, if he is so-inclined to go that route.
0
 

Author Comment

by:Network_Padawan
ID: 35153157
Hi powers,

Its a perc 7 card I believe
0
 
LVL 47

Accepted Solution

by:
dlethe earned 105 total points
ID: 35153726
You really should just leave it alone BUT ...
Use the RAID1 for scratch table space; swap files; transaction logs; any write-intensive items.  Then not only do you accomplish "freeing up the space for data", but you also take advantage of the inherent write speed advantage of RAID1 over RAID5.

RAID10 is NOT going to be faster across the board, because on your O/S disk you're going to be doing a lot of 4KB I/Os.  If you so much as touch a file, and your stripe size in the RAID is 64KB, then you'll be forced to write 128KB worth of data every time.   RAID10 is better for a SQL database but not the boot drive, at least from the I/Os per second perspective.

Personally, I would leave things as they are.
0
 

Author Closing Comment

by:Network_Padawan
ID: 35177105
Thanks guys. Will just leave it as is.
0

Featured Post

Portable, direct connect server access

The ATEN CV211 connects a laptop directly to any server allowing you instant access to perform data maintenance and local operations, for quick troubleshooting, updating, service and repair.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article explains how to install and use the NTBackup utility that comes with Windows Server.
Concerto Cloud Services, a provider of fully managed private, public and hybrid cloud solutions, announced today it was named to the 20 Coolest Cloud Infrastructure Vendors Of The 2017 Cloud  (http://www.concertocloud.com/about/in-the-news/2017/02/0…
This tutorial will show how to push an installation of Backup Exec to an additional server in both 2012 and 2014 versions of the software. Click on the Backup Exec button in the upper left corner. From here, select Installation and Licensing, then I…
This tutorial will walk an individual through the steps necessary to join and promote the first Windows Server 2012 domain controller into an Active Directory environment running on Windows Server 2008. Determine the location of the FSMO roles by lo…

751 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