Re: loader.conf and rootdev option for memory disk

From: Chlasták_Miroslav <mira_at_chlastak.cz>
Date: Sat, 19 Nov 2022 21:31:42 UTC
Look at the file /boot/defaults/loader.conf:

…
###  Initial memory disk settings  ###########################
#mdroot_load="YES"              # The "mdroot" prefix is arbitrary.
#mdroot_type="md_image"         # Create md(4) disk at boot.
#mdroot_name="/boot/root.img"   # Path to a file containing the image.
#rootdev="ufs:/dev/md0"         # Set the root filesystem to md(4) device.
…

—
Mira

> On 19 Nov 2022, at 21:58, Tomoaki AOKI <junchoon@dec.sakura.ne.jp> wrote:
> 
> IIUC, rootdev should be set in loader.env, if needed.
> `man 5 loader.conf` has nothing about rootdev variable.
> 
> (It's undocumented, IIRC.)
> 
> 
> On Sat, 19 Nov 2022 19:57:47 +0100
> Chlasták Miroslav <mira@chlastak.cz <mailto:mira@chlastak.cz>> wrote:
> 
>> I have my device working for now - but the question is - Is the documentation and example for “rootdev” right or not?
>> 
>> —
>> Mira
>> 
>>> On 18 Nov 2022, at 21:13, Warner Losh <imp@bsdimp.com <mailto:imp@bsdimp.com>> wrote:
>>> 
>>> 
>>> 
>>> On Fri, Nov 18, 2022 at 12:57 PM Chlasták Miroslav <mira@chlastak.cz <mailto:mira@chlastak.cz> <mailto:mira@chlastak.cz <mailto:mira@chlastak.cz>>> wrote:
>>> Hi all,
>>> 
>>> In the /boot/defaults/loader.conf are these options for memory disk settings:
>>> 
>>> #mdroot_load="YES"              # The "mdroot" prefix is arbitrary.
>>> #mdroot_type="md_image"         # Create md(4) disk at boot.
>>> #mdroot_name="/boot/root.img"   # Path to a file containing the image.
>>> #rootdev="ufs:/dev/md0"         # Set the root filesystem to md(4) device.
>>> 
>>> 
>>> But - is this example for rootdev option still right? Because “ufs:/dev/md0” works fine on freebsd 12.1, but on freebsd 12.3 this does not work and generates error message:
>>> 
>>> Can’t determine root device
>>> 
>>> 
>>> When I use this option with value “/dev/md0” or “md0” (even with this option commented out), so the machine boots correctly without any error.
>>> 
>>> I think you want vfs.root.mountfrom= instead of rootdev= here.
>>> 
>>> Warner
>>> 
>>> —
>>> Mira
>> 
> 
> 
> -- 
> 青木 知明  [Tomoaki AOKI]    <junchoon@dec.sakura.ne.jp <mailto:junchoon@dec.sakura.ne.jp>>