# RAID 1 on the boot disk



## cedivad (Mar 10, 2012)

I'm having problems configuring hardware RAID 1 for the boot, so *I* need to use the software one alternative. I read that FreeBSD 9 is not compatible with GEOM, how should *I* set up grad? I've already installed the system on one disk.

Many thanks.


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## ctengel (Mar 11, 2012)

Where are you reading that FreeBSD 9 is not compatible with GEOM?  Although I haven't actually tried it yet, I've been told that gmirror(8) is the way to go.


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## cedivad (Mar 11, 2012)

On the manual. However *I* solved using a guide online to setup ZFS RAID 1.


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## phoenix (Mar 12, 2012)

FreeBSD 9 is fully compatible with GEOM.  It's how *all* disk devices are accessed, after all.  

You're thinking of the "GEOM mirroring (gmirror(8)) is not compatible with GPT partitioning" issue.  Which means you can't use gmirror to mirror entire disks, and then use GPT to partition the mirror device.

However, so long as your disks are under 2 TB in size, you can still use gmirror to mirror the entire drives, and use old-school MBR partitioning and BSD labelling of the mirror device. Or, create a single GPT partition that covers the entire drive, and then mirror that partition using gmirror. Or, use ZFS to mirror the drives. Or, use a hardware RAID controller to mirror the drives.

All of the above solutions use GEOM.


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## nomoo (Apr 2, 2012)

I decided to ask in this thread. As far as I understand "gmirror and gpt partitioning" is a working solution but I'll get corrupted gpt restore info at the end of disk, am I right? I've set up few 8.2 servers with such scheme and gmirror is working. 

The only issue *I*'m thinking about in mirroring different partitions - freebsd-boot partition and how will the system boot after primary drive crash.

GPT labels are too handy to work with old-school MBR.

So the question - is it dangerous to have corrupted backup GPT record or not?

P.S. Are there any success stories with hotswap drives and freebsd FreeBSD?


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## wblock@ (Apr 2, 2012)

nomoo said:
			
		

> The only issue i'm thinking about in mirroring different partitions - freebsd-boot partition and how will the system boot after primary drive crash.



Assuming you're talking about mirroring GPT partitions here, he boot partition can be mirrored.  There's not much point, because it doesn't change.  If both drives are set up the same to begin with, that data has already been manually mirrored.

If the primary drive fails, it's up to the BIOS which drive boots.  There's no way around that short of a hardware RAID controller.



> gpt labels are too handy to work with old-school mbr.



Filesystem labels work just as well, and are available with MBR.



> So the question - is it dangerous to have corrupted backup gpt record or not?



Some would say having any corrupted disk structure is dangerous.


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