Re: RFC: Project geom-events

Hello, Miroslav.
You wrote 5 октября 2011 г., 1:27:03:

> I am still missing one thing - dropped provider is not marked as failed
> RAID provider and is accessible for anything like normal disk device. So
> in some edge cases, the system can boot from failed RAID component 
> instead of degraded RAID. This can cause data loss or demage.
  What RAID do you mean exactly? geom_stripe? geom_mirrot? geom_raid?
Something else? If GEOM class drops underlying provider due to errors,
it doesn't have chances to update metadata for it.
  But most of classes, if dropped provider attached again, will
rebuild itself, as they track which components are actual and which
ones are old.
  Do you want GEOM classes to track droppen components somewhere else
and din't even try to attach them automaticaly when they re-appear?

> Is it possible to fix it by something like your geom-events, or should
> it be done in each GEOM RAID class separately?
  geom-events only process events from GEOM classes in userland. Each
 class should decide what happens to him by itself, as only class
 itself knows is this particular error fatal or not.
  geom-events could help, if it replaces dropped component fith spare
 drive, as in such case most classes prefer "latest" drive, not old
 one. Without spares, everything will be exactly as it is now, plus
 e-mails to administrator :)


-- 
// Black Lion AKA Lev Serebryakov <lev_at_FreeBSD.org>