Boot with a degraded raid 5

[Phillip Susi]

Ben Ben wrote:
> What is a known issue ? Running a degraded raid 5 at boot is not possible ?

Known issue that by default, the system will not try to activate the 
array in a degraded state.

> All these test have been done with all 3 disks up, and with --run
> option for mdadm in /etc/udev/rules.d/85-mdadm.rules.
> You can see that md0 is never ran, and md1 (raid0) is sometime ran,
> sometimes not.
> Here, if I stop and launch manually the md, it works.
> 
> If I give the option --no-degraded to mdadm, it work always (if the
> array is not degraded).

Simply removing the --no-degraded option should do the trick.

> Another question : you said I can run the array manually and launch
> back the boot process. How can I do this last point ? running /init ?

IIRC, simply exiting from the busybox shell will cause the boot process 
to attempt to continue, so after you manually assemble the array, just exit.