Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
?
Solved

RAID 5 or 6 for large partition?

Posted on 2011-03-02
7
Medium Priority
?
470 Views
Last Modified: 2016-12-08
I'm rebuilding an array and am debating on RAID 5 or RAID 6.  Here's the requirements:
This server is very heavy on Writes, but not many Reads (it's a video recording server for our security cameras).  The application requires a single volume and can't write to multiple logical drives.  The drive will be full within 30 days and will then use a FIFO rotation scheme.  The total capacity has to be in the 2.5TB range.  I have (8) 450G drives to work with in an HP MSA60 chassis connected to a DL380 G4 running Windows 2003 R2.

Because my volume is over 2T, I'm using a GPT partition table vs MBR, but that shouldn't really matter in this scenario.

I could go with a single RAID 6 config with 2 hot spares, that will give me about 2.5T (6*450- 5%).

Or I could go with 2 RAID 5 arrays then span them in the OS to give me 2.5T (3*450 - 5% * 2).

What I'm really concerned about is the rebuild time if loose a drive.  At 4G per hour, it will take almost 30 days to rebuild parity - probably more because of the sheer volume of data that is replaced every day.  Is it better to have 2 spares in RAID 6, or smaller parity rebuild by using 2 RAID 5?  I've never been a fan of spanning partitions, how does that play into this equation?

Other recommendations?

Tim
0
Comment
Question by:hundet
7 Comments
 
LVL 2

Expert Comment

by:BITCooler
ID: 35018046

Consider RAID 50 = Good Balance of Space utilizationi, Redundancy, and Write Performance.

I recently setup an HP Proliant DL380 G7 server 88GB DDR3 RAM with the following RAID config:
RAID 50 based on:
8 x 300GB 10,000 SAS drives
HP P410i Controller 1GB cache

Cache on your controller will make a huge difference.  Add as much as you can afford.

For the moment, I'm running a Citrix Xenserver 5.6 FP1 with Windows SBS 2008 installed as a Virtual Machine.
0
 
LVL 2

Expert Comment

by:Xav720
ID: 35018103
user raid 50 for performance but if is not a performance issue use  raid 5
0
 
LVL 2

Assisted Solution

by:BITCooler
BITCooler earned 1000 total points
ID: 35018203
I should point out, that I paid extra for the HP Smart Array Advanced Pack (HP Part Number 516471-B21) to unlock other features of the P410i controller.  This may have given me the RAID 50 choice.

A good source for making RAID knowledge is http://www.acnc.com/04_01_05.html

If you consider RAID 50 it's worth while reading this article from TechRepublic:
http://www.techrepublic.com/blog/datacenter/raid-50-offers-a-balance-of-performance-storage-capacity-and-data-integrity/2822

RAID 3 is suppose to be good for video streaming.

RAID 10 will give you better performance, but you will take a hit on available storage capacity.
0
VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

 
LVL 42

Accepted Solution

by:
kevinhsieh earned 1000 total points
ID: 35018271
Spanning in the OS isn't a good idea. Better to do RAID 50 at the controller level. RAID 6 will give the same capacity as RAID 50 and I think is preferable because you are less vulnerable in case of drive failure. Your video recording system may generate a lot of throughput, but the IOPS should be low which makes plays to the strength of RAID 6. I use RAID 6 with 8 2TB drives in my backup server and throughput is very good.

I am not familiar with the HP line, but my understanding is that RAID performance sucks unless your controller has battery backed cache. If you haven't already bought your drives I would look for 7.2K RPM nearline SAS drives which are perfect for your application. 10K SAS is overkill for this.
0
 
LVL 56

Expert Comment

by:Handy Holder
ID: 35035934
Can you afford RAID 10? Rebuild time is hours rather than days. Plus for video recording you could use 2TB midline SAS rather than enterprise SAS since it's sequential write so not much disk head movement.
0
 
LVL 56

Expert Comment

by:Handy Holder
ID: 35035952
Sorry kevinhsieh, you already said use 7.2K disks for video.
0
 

Author Closing Comment

by:hundet
ID: 35059145
Went with RAID 6 - already had all the hardware, and it seems to be performing better than the original RAID 5 that we tried.

Thanks for all the comments.
0

Featured Post

Concerto Cloud for Software Providers & ISVs

Can Concerto Cloud Services help you focus on evolving your application offerings, while delivering the best cloud experience to your customers? From DevOps to revenue models and customer support, the answer is yes!

Learn how Concerto can help you.

Question has a verified solution.

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

Backups and Disaster RecoveryIn this post, we’ll look at strategies for backups and disaster recovery.
Among the most obnoxious of Exchange errors is error 1216 – Attached Database Mismatch error of the Jet Database Engine. When faced with this error, users may have to suffer from mailbox inaccessibility and in worst situations, permanent data loss.
This video teaches viewers how to encrypt an external drive that requires a password to read and edit the drive. All tasks are done in Disk Utility. Plug in the external drive you wish to encrypt: Make sure all previous data on the drive has been …
This tutorial will walk an individual through the process of installing the necessary services and then configuring a Windows Server 2012 system as an iSCSI target. To install the necessary roles, go to Server Manager, and select Add Roles and Featu…
Suggested Courses
Course of the Month11 days, 5 hours left to enroll

572 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