Re: degraded permanent mount option

[Christophe Yayon <cyayon@nbux.org>]

I just tested to boot with a single drive (raid1 degraded), even with degraded option in fstab and grub, unable to boot ! The boot process stop on initramfs.

Is there a solution to boot with systemd and degraded array ?

Thanks 

--
Christophe Yayon

> On 27 Jan 2018, at 07:48, Christophe Yayon <cyayon@nbux.org> wrote:
> 
> I think you are right, i do not see any systemd message when degraded option is missing and have to remount manually with degraded.
> 
> It seems it is better to use mdadm for raid and btrfs over it as i understand. Even in recent kernel ?
> I hav me to do some bench and compare...
> 
> Thanks
> 
> --
> Christophe Yayon
> 
>> On 27 Jan 2018, at 07:43, Andrei Borzenkov <arvidjaar@gmail.com> wrote:
>> 
>> 27.01.2018 09:40, Christophe Yayon пишет:
>>> Hi, 
>>> 
>>> I am using archlinux with kernel 4.14, there is btrfs module in initrd.
>>> In fstab root is mounted via UUID. As far as I know the UUID is the same
>>> for all devices in raid array.
>>> The system boot with no problem with degraded and only 1/2 root device.
>> 
>> Then your initramfs does not use systemd.
>> 
>>> --
>>> Christophe Yayon
>>> cyayon-list@nbux.org
>>> 
>>> 
>>> 
>>>>> On Sat, Jan 27, 2018, at 06:50, Andrei Borzenkov wrote:
>>>>> 26.01.2018 17:47, Christophe Yayon пишет:
>>>>> Hi Austin,
>>>>> 
>>>>> Thanks for your answer. It was my opinion too as the "degraded"
>>>>> seems to be flagged as "Mostly OK" on btrfs wiki status page. I am
>>>>> running Archlinux with recent kernel on all my servers (because of
>>>>> use of btrfs as my main filesystem, i need a recent kernel).> >
>>>>> Your idea to add a separate entry in grub.cfg with
>>>>> rootflags=degraded is attractive, i will do this...> >
>>>>> Just a last question, i thank that it was necessary to add
>>>>> "degraded" option in grub.cfg AND fstab to allow boot in degraded
>>>>> mode. I am not sure that only grub.cfg is sufficient...> > Yesterday, i have done some test and boot a a system with only 1 of
>>>>> 2 drive in my root raid1 array. No problem with systemd,>
>>>> Are you using systemd in your initramfs (whatever
>>>> implementation you are> using)? I just tested with dracut using systemd dracut module and it
>>>> does not work - it hangs forever waiting for device. Of course,
>>>> there is> no way to abort it and go into command line ...
>>>> 
>>>> Oh, wait - what device names are you using? I'm using mount by
>>>> UUID and> this is where the problem starts - /dev/disk/by-uuid/xxx will
>>>> not appear> unless all devices have been seen once ...
>>>> 
>>>> ... and it still does not work even if I change it to root=/dev/sda1
>>>> explicitly because sda1 will *not* be announced as "present" to
>>>> systemd> until all devices have been seen once ...
>>>> 
>>>> So no, it does not work with systemd *in initramfs*. Absolutely.
>>> 
>>> 
>> 
> 
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