Re: Avoid wedges from certain devices

[mlelstv%serpens.de@localhost (Michael van Elst)]

martin%duskware.de@localhost (Martin Husemann) writes:

>On Sat, Feb 29, 2020 at 09:41:46PM -0000, Michael van Elst wrote:
>> From the description it looks like he is using ataraid (ld0) and
>> also sees the components (wd0 and wd1).

>Duh. Can't the ataraid driver detect this and mark/block the components?

Can raidframe do this with its components? The encapsulation (raidframe
label) just protects it from such an issue.

atabus currently does:

- attach wd drives
- if controller can do RAID:
      try to attach ataraid

it would need to do:

- attach wd drives without scanning wedges
- if controller can do RAID:
      try to attach ataraid
      if failed:
          scan for wedges on wd
  else
      scan for wedges on wd

or less pleasing:

- attach wd drives
- if controller can do RAID:
      try to attach ataraid
      if successful:
         remove wedges from components

Manually scanning for wedges is simple.
Attaching a drive without scanning for wedges needs a new mechanism.


On the other hand, if we ever support something like multipathing, it
becomes necessary to identify and handle such aliases generally.

-- 
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."