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


What is the best array for installing server OS or DATA partition, RAID 1 or RAID 5?

Posted on 2012-08-24
Medium Priority
Last Modified: 2016-12-08

My question is as follows. Is there a "better" choice for installing the server OS? I know some people recommend installing the SERVER OS in a RAID 1 DISK and the data in a different RAID 1 or a RAID 5 array. But is it just as well if you simply create a single RAID 5 array and install OS and DATA there (in different partitions though...)

I would like to know what is the general consensus for different types of server installations...

Question by:profanostra
  • 2
LVL 20

Assisted Solution

wolfcamel earned 400 total points
ID: 38331665
seperate raids will give better performance than seperate drives on the one raid.
consider a raid as one drive - it isnt ideal to put the two partitions on the one drive.

then the type of raid for each drive will depend on the application but this is what I like..

OS - 2 drives - Raid1
Data - 4 drives - raid 10
Other- 2drives raid1 - or one drive - on here I put the data that either I never want to back up or stuff that is irrelevant to backup. Such as antivirus, and WSUS, and some temp work space.
As I use an imaging product for backup (storage craft) and backup changes every 15min this keeps data that changes often on a different drive and makes my incremental backups smaller/more relevant
LVL 47

Accepted Solution

David earned 400 total points
ID: 38331671
"Best" is relative, so I'll make this rather generic for typical office database general purpose server running Win2K8, or any *NIX

Go RAID1 for the O/S, using either a quality controller with battery backup, or host-based RAID.  With either, you get read load balancing, so in perfect world read performance is 2X that of a single drive.  Write performance is close to the same as if you had a single drive.

There is NO significant CPU overhead if you do any type of software RAID. RAID calculations are done in microseconds and nanoseconds.

RAID5 is great for high throughput read, but bad to worse in random and sequential I/O.  RAID5 is much worse when you are degraded and have to rebuild.  I've seen it take over a week in some cases.

Personally, one should never do RAID5 anymore.  I recommend RAID1 for O/S, swap, scratch index/tables, and journals.  Then use RAID6 for data.  That way you are protected against data loss in event of a multiple drive failure.

Also consider a pair of small SSDs with host-based RAID on your SATA ports.  $1000 will get you almost 50,000+ random I/Os per second, all 100% protected.

If you're talking a 10-200+ Terabyte server then I would recommend some tweaks and get into these items in depth, but that depends on a lot more variables about intended use.
LVL 20

Expert Comment

ID: 38331674
of course if you are looking for capacity& redundancy for the best $ then one raid 5 array - but it wont give the best performance for your $

Author Closing Comment

ID: 38331688
Wow, excellent viewpoints and suggestions! Thank you very much for your comments gentlemen.
Have a good weekend.

Featured Post

Transaction-level recovery for Oracle database

Veeam Explore for Oracle delivers low RTOs and RPOs with agentless transaction log backup and transaction-level recovery of Oracle databases. You can restore the database to a precise point in time, even to a specific transaction.

Question has a verified solution.

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

When we purchase storage, we typically are advertised storage of 500GB, 1TB, 2TB and so on. However, when you actually install it into your computer, your 500GB HDD will actually show up as 465GB. Why? It has to do with the way people and computers…
In this article we will learn how to backup a VMware farm using Nakivo Backup & Replication. In this tutorial we will install the software on a Windows 2012 R2 Server.
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

581 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