https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=232835
Bug ID: 232835
Summary: [gmirror] gmirror fails to recover from degraded
mirror sets in some circumstances (2/n)
Product: Base System
Version: CURRENT
Hardware: Any
OS: Any
Status: New
Severity: Affects Some People
Priority: ---
Component: kern
Assignee: [email protected]
Reporter: [email protected]
CC: [email protected], [email protected]
Depends on: 232671
Blocks: 232683, 232684
This is related to bug 232671 , but not identical.
Here is the example scenario:
1. I start with a GMIRROR with three ACTIVE disks
(sc_ndisks = md_all = 3)
2. I essentially disconnect one of the disks
3. The remaining mirrors lower md_all to 2 and the syncid /
generation gets bumped
4. I reboot, and the removed disk reappears
5. Geom tastes the stale removed disk first, and populates
sc_ndisks from its md_all (3)
6. The two valid mirrors are tasted afterwards and the gmirror
rejects both as having invalid metadata (md_all=2), despite
their having a higher generation / sync id
The problem is basically that gmirror doesn't "upgrade" its metadata
to the newest valid mirrorset it finds -- it just sticks with whatever
it found first.
I think the solution is being a bit clever about detecting the latest
mirror generation while a gmirror is still in the STARTING state;
and also perhaps a little more clever about when we transition from
STARTING to RUNNING (at which point a newer generation mirror showing
up means we have corruption).
Referenced Bugs:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=232671
[Bug 232671] [gmirror] gmirror fails to recover from degraded mirror sets in
some circumstances
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=232683
[Bug 232683] [gmirror] gmirror could provide much better administrative
introspection into decision-making processes
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=232684
[Bug 232684] [gmirror] gmirror overly aggressive provider destruction
--
You are receiving this mail because:
You are on the CC list for the bug.
_______________________________________________
[email protected] mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-geom
To unsubscribe, send any mail to "[email protected]"
