# Configure RAID before Installing Server OS?



## ohs (Jul 20, 2015)

Hello,
I am new to the server world, I have spent most of my time in the networking world and just now am taking on new server roles, so please pardon my ignorance with this topic. 

I have an HP server that was previously used therefore I am going to format and use for a test server. Do I want to boot to my HP SmartStart disc first and then setup my RAID5 (i have 4HDD in HP DL380g6 server) then after the RAID is setup reboot and install my OS? Or should I Install my Server OS first, then set raid via disc management once windows is loaded. I am confused on what are the proper steps on this.


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## Triple6 (Dec 26, 2002)

If the operating system will be installed on a RAID array then you must configure the RAID first, with the exception of RAID-1 which I think you can add after the fact but I'd still do it beforehand. You can do so with the firmware utility or with the SmartStart disc. Additional RAID arrays can be configured after the O/S is installed.


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## ohs (Jul 20, 2015)

What is normal practice, installing OS on a RAID? My goal is if one HDD dies i can hot swap for another.


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## Triple6 (Dec 26, 2002)

Yes, in a server RAID should ideally be used for all drive groups. If you want to be able to swap drives when they fail without downtime then you must use RAID.

There's different ways to setup RAID and servers. It depends on what your goal is, the number of drives, the redundancy you want, the performance you want, etc.

A common setup has been two drives in RAID-1 for the O/S, and 3+ drives for data in RAID-5/6/10, and sometimes even additional arrays for databases. On entry level servers some people just do a RAID-1, RAID-5, or 10 array and the single array hosts the O/S and data.

I'd read up on the different levels and choose one that matches your needs. Also see how many drives you have to work with and what the RAID controller supports. RAID 0 and 1 are pretty much always supported, higher RAID levels like 5 and 10 sometimes require a license key either via software or a hardware key. And if this is an older server or a basic RAID controller it may not support RAID-10/0+1.

I'd do some quick reading on the various RAID levels and what they offer: http://www.adaptec.com/en-us/solutions/raid_levels.html


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## ohs (Jul 20, 2015)

Great, thanks for the advice!


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