SyncMirror
SyncMirror optionally provides redundancy for disk shelves
When SyncMirror is enabled on an aggregate, the aggregate is made up of
two mirrored sets of disks
You need twice as many disks to make a SyncMirror aggregate.
You can enable SyncMirror for selected aggregates on a system or for all of
them
SyncMirror
Along with controller HA, SyncMirror is the enabling technology
for MetroCluster
SyncMirror is always used on MetroCluster systems
It is optional on non-MetroCluster systems
Plexes
The two different mirrored sets of disks that make up a SyncMirror
aggregate are called Plexes
The two plexes are on different shelves connected to the system
with separate cables
Mirrored aggregates cannot have more than two plexes
A normal, non SyncMirrored aggregate has one plex
Pools
To configure SyncMirror, the disks must be divided into two pools
named Pool 0 and Pool 1
Disks for the first plex in a SyncMirror aggregate are assigned from
Pool 0, disks for the second plex are assigned from Pool 1
Pools
When disk auto assignment is turned on, all disks are assigned
to Pool 0
To configure SyncMirror, you have to disable auto assignment,
and manually assign half the disks to Pool 0 and the other half
to Pool 1
Plexes and Pools
Aggr0
Pool 0 – Plex 0
RAID Group 0
Spare Disks
Pool 0
Plexes and Pools
Aggr0
Pool 0 – Plex 0
RAID Group 0
Aggr1
Pool 0 – Plex 0
RAID Group 0
RAID Group 1
Spare Disks
Pool 0
Plexes and Pools
Aggr0
Pool 0 – Plex 0
RAID Group 0
Aggr1
Pool 0 – Plex 0
RAID Group 0
RAID Group 1
Spare Disks
Pool 0
Spare Disks
Pool 1
Plexes and Pools
Aggr0
Pool 0 – Plex 0
RAID Group 0
Aggr1
Pool 0 – Plex 0
RAID Group 0
RAID Group 1
Spare Disks
Pool 0
Spare Disks
Pool 1
Aggr1
Pool 1 – Plex 1
RAID Group 0
RAID Group 1
SyncMirror Recovery
If a plex fails then data requests will be serviced by the remaining plex.
When the failed plex is repaired, the two plexes automatically resync.
If a plex cannot be repaired, destroy it and then recreate with new disks.