SyncMirror management
- What SyncMirror is
SyncMirror is an optional feature of Data ONTAP. You can use SyncMirror to mirror aggregates embedded in traditional volumes and aggregates that contain FlexVol volumes.
- What mirrored aggregates and traditional volumes are
A mirrored aggregate or traditional volume is a single WAFL storage file system with two physically separated and synchronously up-to-date copies on disks. These copies are called plexes. Data ONTAP automatically names the first plex plex0 and the second plex plex1.
- Prerequisites for using mirrored volumes
Before using mirrored aggregates or traditional volumes, you need a SyncMirror license, storage systems that support the SyncMirror feature, and an appropriate configuration of disk shelves.
- Where mirrored volume plexes get their disks
When a mirrored volume is created, Data ONTAP separates spare disks from a collection of disks, called a disk pool, into two disk pools, pool0 and pool1.
- Enabling the SyncMirror license
The license code name for the mirroring feature is syncmirror_local. To enable the mirroring license, complete the following steps.
- Disabling the SyncMirror license for traditional volumes
You cannot disable the mirroring license if mirrored volumes or mirrored aggregates exist and are online. Before disabling the mirroring license, you must take one of the plexes offline for each mirrored volume or mirrored aggregate and destroy it.
- Disabling the SyncMirror license for mirrored aggregates
You cannot disable the mirroring license if mirrored volumes or mirrored aggregates exist and are online. Before disabling the mirroring license, you must take one of the plexes offline for each mirrored volume or mirrored aggregate and destroy it.
- Creation of mirrored aggregates and traditional volumes
You can create a mirrored aggregate or traditional volume using one of the following ways.
- Addition of a plex to an existing unmirrored aggregate or traditional volume
You can add a plex to an existing unmirrored aggregate or traditional volume using one of the following methods.
- Addition of disks to a mirrored aggregate or traditional volume
You can add disks to mirrored aggregate or traditional volumes using the following methods.
- The states of a plex
A plex can either be in an online state or in an offlline state. In the online state, the plex is available for read or write access and the contents of the plex are current. In an offline state, the plex is not accessible for read or write.
- Splitting a mirrored aggregate or traditional volume
Splitting a mirrored aggregate or traditional volume removes the relationship between its two plexes and creates two independent unmirrored aggregates or traditional volumes. After splitting, both the aggregates or traditional volumes come online.
- Rejoining split aggregates or traditional volumes
You might rejoin split aggregates or traditional volumes because you were forced to split them. This would be the case if you have set up an active/active configuration in a MetroCluster configuration and a disaster breaks the active/active configuration.
- Removing a plex from a mirrored aggregate
You might remove a plex from a mirrored aggregate, if there is a problem with that plex.
- Removing a plex from a mirrored traditional volume
You might remove a plex from a mirrored traditional volume, if there is a problem with that plex.
- Comparing plexes of a mirrored aggregate or traditional volume
The plexes of a mirrored aggregate or traditional volume are almost always synchronized. Therefore, there is rarely need to compare the plexes of a mirrored aggregate or traditional volume.
