# Is it possible to create raid 1 from disks partitions?



## nikitastepanov (Mar 15, 2020)

And can freebsd boot from software raid 1?


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## Phishfry (Mar 15, 2020)

I don't know if gmirror(raid1) supports partitions but you can boot from gmirror arrays.








						Install UEFI FreeBSD on gmirror
					

I wanted to post instruction for installing FreeBSD on a GEOM_MIRROR  -aka- gmirror(8). This is an advanced topic so I assume you are capable of determining that your two chosen disks are empty. UFS RAID1 on FreeBSD is enabled with the geom_mirror module. I am using ada0 and ada1 as examples...




					forums.freebsd.org
				




Think of it this way; gmirror is used for redundancy.
If one disk craps out another disk has the same information and you can still run FreeBSD.
With one drive gmirror what happens when a drive dies? You lose everything. So the concept is unsound.
If you used gmirror partitions on two disks that would be acceptable.

This is similar to the question; Can I have gstripe(raid0) on partitions.
Disk drives can only read from one section of the disk at a time. They have a gmr head on an arm over the platters.
With raid0 on partitions on a single disk you would have to be reading from two separate areas at one time.
I would suspect that raid0 on single disk partitions would actually be slower than a single drive with no raid0.


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