When creating your DataKeeper resource hierarchy, LifeKeeper will prompt you to select a resource type. There are several different DataKeeper resource types. The following information can help you determine which type is best for your environment.
Replicate New File System
Choosing a New Replicated File System will create/extend the NetRAID device, mount the given mount point on the NetRAID device and put both the LifeKeeper supported file system and the NetRAID device under LifeKeeper protection. The local disk or partition will be formatted.
When this resource is extended to the second node, it will not do a full resync but only the file system metadata data. However when it is extended to the 3rd or more node, a full resync will be done to that node. To avoid a full resync, please follow the directions provided in Avoiding Full Resynchronizations.
Replicate Existing File System
Choosing Replicate Existing File System will use a currently mounted disk or partition and create a NetRAID device without deleting the data on the disk or partition. SIOS DataKeeper will unmount the local disk or partition, create the NetRAID device using the local disk or partition and mount the mount point on the NetRAID device. It will then put both the NetRAID device and the LifeKeeper supported file system under LifeKeeper protection.
Choosing a DataKeeper Resource will create/extend the NetRAID device and put it under LifeKeeper protection without a file system. You might choose this replication type if using a database that can use a raw I/O device.
In order to allow the user continued data access, SIOS DataKeeper will not attempt to unmount and delete a NetRAID device if it is currently mounted. The user must manually unmount it before attempting a manual switchover and mount it on the other server after the manual switchover.
Note: After the DataKeeper resource has been created, should you decide to protect a manually mounted file system with LifeKeeper, you can do so as follows:
- Format the NetRAID device with a LifeKeeper supported file system.
- Mount the NetRAID device.
- Create and extend a file system hierarchy using the NetRAID device as if it were a shared storage disk or partition.
LifeKeeper’s file system recovery kit will now be responsible for mounting/unmounting it during failover.