Re: How to delay mdadm assembly until all component drives are recognized/ready?

[Ram Ramesh <rramesh2400@gmail.com>]

On 05/09/2017 10:13 PM, Ram Ramesh wrote:
> Today, I noticed that my RAID6 md0 was assembled in degraded state 
> with two drives in failed state after a pm-suspend and restart. Both 
> of these drives were attached toSAS9211-8I controller. The other 
> drives are attached to motherboard. I have not had this on a normal 
> boot/reboot. Also, in this particular case, mythtv recording was going 
> on when suspended and therefore as soon as resumed that used this md0.
>
> Upon inspection, it appears (I am not sure here) that mdadm assembled 
> the array even before the drives were ready to be used. All I had to 
> do was to remove and re-add them to bring the array back to "good" 
> state. I am wondering if there is a way to tell mdadm to wait for all 
> drives to be ready before assembling. Also, if there is something that 
> I can add to resume scripts that will help, please let me know.
>
> Kernel: Linux zym 3.13.0-106-generic #153-Ubuntu SMP
> mdadm - v3.2.5 - 18th May 2012
>
> Failed drives are HGST NAS and WD Gold with less than a year of usage. 
> So I doubt they are bad drives by any means.
>
> Ramesh
>
>
This happened again. I think no damage is done until I write to the 
device. Once the write fails, it marks the component disk "failed" If I 
can make it wait a shortwhile before writing happens, I think I should 
be ok. Is there something possible with any of the thaw scripts that 
will delay start of resume operation.

Ramesh