We help IT Professionals succeed at work.

RAID 5 and RAID 1 question

kam_uk
kam_uk asked
on
532 Views
Last Modified: 2013-11-14
Hi

We have a server that has 5 SCSI disks.

Normally, we create one RAID 1 mirrored paired for the OS (disks 0 and 1), and then the remaining 3 are used in a RAID 5 setup for the application.

However, I was thinking about this....what's the actual advantage of having the OS on a mirrored pair. Surely, if all 5 disks were in a RAID 5, then we could lose one anyway? Why the seperation?

Secondly, can one Array Controller service as many disks into different RAID configurations as needed? I.e. will one Array Controller be sufficient for the above in a RAID 1 and RAID 5 setup?

Finally, out of RAID 1 and RAID 5, which one is better for an application that writes a lot, and which one is better for an application that reads a lot?

I'm not a hardware person at all, so any help appreciated.
Comment
Watch Question

This one is on us!
(Get your first solution completely free - no credit card required)
UNLOCK SOLUTION
This one is on us!
(Get your first solution completely free - no credit card required)
UNLOCK SOLUTION

Author

Commented:
Thanks..and just to confirm, out of RAID 1 and RAID 5, which one is better for reading and which one is better for writing? And why?

Author

Commented:
Also, Prelude218, you say

"Back in the days of NT4, this was a common setup, OS on one partition and data and programs on another partition (or raid set). "

So, what has changed? Why is this not a common set up anymore?
Raid 5 is way faster for reading and writing.

Simply put, if you are spreading data over say...5 different HDD's and you want pieces off each HD, you will get that information 5x faster because it doesn't have to wait for the first piece to access the second piece, it can access both pieces at the same time
Commented:
This one is on us!
(Get your first solution completely free - no credit card required)
UNLOCK SOLUTION
andyalderretired saggar maker
CERTIFIED EXPERT
Distinguished Expert 2019
Commented:
This one is on us!
(Get your first solution completely free - no credit card required)
UNLOCK SOLUTION

Gain unlimited access to on-demand training courses with an Experts Exchange subscription.

Get Access
Why Experts Exchange?

Experts Exchange always has the answer, or at the least points me in the correct direction! It is like having another employee that is extremely experienced.

Jim Murphy
Programmer at Smart IT Solutions

When asked, what has been your best career decision?

Deciding to stick with EE.

Mohamed Asif
Technical Department Head

Being involved with EE helped me to grow personally and professionally.

Carl Webster
CTP, Sr Infrastructure Consultant
Empower Your Career
Did You Know?

We've partnered with two important charities to provide clean water and computer science education to those who need it most. READ MORE

Ask ANY Question

Connect with Certified Experts to gain insight and support on specific technology challenges including:

  • Troubleshooting
  • Research
  • Professional Opinions
Unlock the solution to this question.
Join our community and discover your potential

Experts Exchange is the only place where you can interact directly with leading experts in the technology field. Become a member today and access the collective knowledge of thousands of technology experts.

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.