Sun Microsystems 5310 NAS manual Checkpoint Scheduling, Checkpoint management commands

6.1.2.5Checkpoint Scheduling

Checkpoints can be created in two ways: automatic and manual. If the user selects the automatic checkpoints, checkpoints are created and removed based on the scheduling that user specifies for the checkpoints. This scheduling is enforced by a checkpoint manager thread. On the other hand, checkpoint manager does not control manually created checkpoints (users can create manual checkpoints that will be removed automatically by using the same naming convention that system uses for automatic checkpoints).

Also there is a feature (currently disabled) that allows the root user of an NFS client to create manual checkpoints. If the root user creates a directory in the root directory of a CFS, it will be interpreted as a request for creation of a new checkpoint and a checkpoint with specified name will be created.

6.1.2.6Checkpoint management commands

In order to manage checkpoints, the following commands are provided in StorEdge Command Line interface (CLI):

chkpnt : A general command for changing different checkpointing options

chkpntls: Shows the status of checkpoints along with a list of exiting checkpoints

chkpntmk: Creates a new checkpoint

chkpntmv: Renames an existing checkpoint

chkpntoff: Disables checkpoints on a volume. This will remove all the checkpoints and frees up all the allocated resources

chkpnton: Enables checkpoint on a volume. Does not create any checkpoints

chkpntrm: Removes a checkpoint.

6.1.2.7Local Directory Checkpoint Access

Checkpoints are read-only point-in-time images of a volume. They can either create manually or schedule to be create and remove by the system without user intervention. Checkpoints are accessible in two ways:

■Via the standard mechanism of mapping or mounting the virtual volume

■Via the local directory checkpoint access feature

The local directory checkpoint access feature allows the users access any version of a directory by simply using normal client commands. This white paper describes the access of checkpoints using the local directory checkpoint access feature and provides usage examples.

Chapter 6 Checkpoints/Snapshots 6-11