# Install FreeBSD 11 on  Intel RST based raid 5



## leveraction (Mar 6, 2017)

Hello all.  This is my first post.  I have considered giving FreeBSD a try for a while and have decided now would be a good time although I may have bitten off more than I can chew.

I am trying to install the OS on my fake raid but it is not working.  I don't even know if it is possible in this configuration.

I have a new server box with the onboard Intel Rapid Storage Technology (RST) raid controller. (I believe this is knowns as 'fake raid')  You can access the Intel RST software preboot with a special key combination.  I have done this and quite easily set up a single RAID 5 array. (4 SSD discs, 500 GB each, the raid covers all my discs.).

I then attempted to install FreeBSD but when I get to the part about partitioning the (RAID) disc (either manual or Auto) I get an error message that says:

"Read-only file system. geom 'raid/r0"  

It appears the installer recognizes the RAID bit cannot write to it.  Can anyone help out?

P.S. - I know that one option is to disable the fake raid and do a pure software raid.  It may come to that, but the Intel software was very easy to use and if it is possible I would like to stick with it.


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## lostpacket (Mar 7, 2017)

I would highly recommend staying away from the fake raid option, and create a software raid volume via zfs for example. The main issue you will have using the fake raid controller is when it comes to monitoring it, you'll find there's no way of monitor the state of the raid array as there's no support for it. 

Maybe I am wrong, but this is my experience with these things, we have a couple of servers in the field I cannot monitor the drive states because they are using fake raid, I can't find anyway of finding something which will read the drive.


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## VladiBG (Mar 7, 2017)

Hello Leveraction,
You need to know that if you are using Intel Raid for RAID5 you will not have controller write cache therefore your write performance will be impacted. If you plan to use Raid5 look for hardware based raid controller that included Write-back Cache with write-cache batteries. You can find the list of supported raid controllers at https://www.freebsd.org/relnotes/CURRENT/hardware/support.html

After FreeBSD 9.1 geom_raid driver is included in the kernel and you can create, monitor or recover your raid volume from the console. I will suggest not to use the Intel boot menu (ctrl+I) to create the raid volume. It's better to boot to the shell and play a little with the graid command. You can read more athttps://www.freebsd.org/doc/handbook/geom-graid.html

After you feel comfortable with the graid command and create your raid volume, exit back to the install shell and continue the installation.

To monitor the status of the raid volume use:
`graid status`


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## leveraction (Mar 7, 2017)

Yes, I think you guys are right.  Now I am trying to go the graid option as my frustration level with the fake raid has hit its limit.  Now I have run into a problem with trying to make a new raid and getting errors concerning meta data already existing on the drive from the previous raid setup.  I think one of the 'g' commands has a clean option which I am going to start messing around with. Thanks for the pointers.  I am sure you will be hearing again from me shortly.


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## leveraction (Mar 7, 2017)

A quick follow up for some other frustrated soul out there trying to install a raid.  I ended up installing RAID Z1 across my four SSDs using the standard installer and it was very easy.  If you have no idea what ZFS is and thus want to avoid it, you should reconsider.  Let me recommend the tutorial I used to familiarize myself with the basics:  
http://buildwithbsd.org/zfs/zfs_tutorial_part_1.html  by Will Green
I think it is excellent and even has a picture to help explain things.  It was really easy.  Also, thumbs up for FreeBSD documentation.  The man pages are actually worth reading; much better than with any Linux distro I have used.


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