# The problem with gmirror (softRAID1) after updating FreeBSD 11 to FreeBSD 12



## golovinov_igor (Feb 25, 2019)

Good day. After assembling the world and the kernel and installing them, the system could not start.
When the kernel comes to mount a partition root, it is suggested to choose a file system for mounting. If I choose /dev/mirror/gm0a, the system continues to boot, as if there are no problems.

I come across this for the first time and I don’t know how to explain this.

# cat /etc/fstab
# Device            Mountpoint  FStype  Options Dump    Pass#
/dev/mirror/gm0a    /               ufs        rw      1       1
/dev/mirror/gm0b    none        swap    sw      0       0

Thank you very much for your answers!


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## PMc (Feb 25, 2019)

As far as I remember, it is the loader that greps into /etc/fstab and determines the root filesystem. This name is then stored into a kenv variable ("vfs.root.mountfrom=ufs:/dev/mirror/whatever").
In your case that variable seems not to exist, so somehow this fails (can the loader read /etc/fstab from the device where the loader and kernel is fetched?)
Otherwise You might give it a try and set that variable explicitely in loader.conf, to see if that works.


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## golovinov_igor (Feb 26, 2019)

Very strange, this variable is not in the previous version. Reassemble RAID1 again?


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## PMc (Feb 26, 2019)

Checking changes between R11 and R12 in that aera... there were a couple of changes nearby (e.g loader support for geli).

The "vfs.root.mountfrom" does exist in 11.2 - I dont have an R12 in reach (as I currently tend to go for 12.1 rather).
The whole scheme was always a bit of a hattrick, sparsely documented, and more or less problematic (e.g. how would the loader read /etc/fstab from a filesystem that needs some kernel module to be understood?).

Here is the information I rely on - a bit oldfashioned, indeed.


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