gmirror and graid3 in a way that it is not resynchronized after a
power failure or system crash.
It is safe when gjournal is running on top of gmirror/graid3.
which means that devices will be destroyed on last close.
This fixes destruction order problems when, eg. RAID3 array is build on
top of RAID1 arrays.
Requested, reviewed and tested by: ru
MFC after: 2 weeks
Submitted by: green
- Speed up synchronization process by using configurable number of I/O
requests in parallel.
+ Add kern.geom.raid3.sync_requests tunable which defines how many parallel
I/O requests should be used.
+ Retire kern.geom.raid3.reqs_per_sync and kern.geom.raid3.syncs_per_sec
sysctls.
- Fix race between regular and synchronization requests.
- Reimplement raid3's data synchronization - do not use the topology lock
for this purpose, as it may case deadlocks.
- Stop synchronization from pre-sync hook.
- Fix some other minor issues.
Tested by: Mike Tancsa <mike@sentex.net>
MFC after: 3 days
means that old problem was triggered (when two providers end at the same
offset, eg. ad0 and ad0s1 and the wrong was is picked up by gmirror/graid3).
Reported by: Michal Suszko <dry@dry.pl>
MFC after: 3 days
(we ignore it).
- Remove code used for handling spoil events, as spoiling is not possible
anymore, because we keep consumers open for writing all the time.
MFC after: 4 days
After this change, when component is disconnected because of an I/O error,
it will not be connected and synchronized automatically, it will be logged
as broken and skipped. Autosynchronization can occur, when component is
disconnected (on orphan event) and connected again - there were no I/O
error, so there is no need to not connected the component, but when there were
writes while it wasn't connected, it will be synchronized.
This fix cases, when component is disconnected because of I/O error and can be
connected again and again.
- Bump version number.
- Implement backward compatibility mechanism. After this change when metadata in
old version is detected, it is automatically upgraded to the new (current)
version.
verification of regular data when device is in complete state.
On verification error, EIO error is returned for the bio and sysctl
kern.geom.raid3.stat.parity_mismatch is increased.
Suggested by: phk
as well, even if device is in complete state.
I observe 40% of speed-up with this option for random read operations,
but slowdown for sequential reads.
Basically, without this option reading from a RAID3 device built from 5
components (c0-c4) looks like this:
Request no. Used components
1 c0+c1+c2+c3
2 c0+c1+c2+c3
3 c0+c1+c2+c3
With the new feature:
Request no. Used components
1 c0+c1+c2+c3
2 (c1^c2^c3^c4)+c1+c2+c3
3 c0+(c0^c2^c3^c4)+c2+c3
4 c0+c1+(c0^c1^c3^c4)+c3
5 c0+c1+c2+(c0^c1^c2^c4)
6 c0+c1+c2+c3
[...]
