Configuring the DS-System : Updating the DS-System configuration file parameters : Using an automated script to lock storage
 
Using an automated script to lock storage
This feature is designed to interact with a third-party application, allowing the snapshot to run unattended, on schedule.
Instead of manually clicking / unclicking the Lock buttons, the DS-System database (database name = “dssystem”) provides a table called “storage_lock” that will respond to third-party manipulation.
The “storage_lock” table has two columns:
 
column name
Description
lock_cmd
This value must be set by the third-party application.
1 = lock (all attempts to change the online storage will be paused)
2 = unlock (instructs DS-System to release the online storage for normal operation)
lock_status
The third-party application must wait until this value changes from “0” before performing the snapshot. This may take a few moments in an N+1 configuration (where multiple nodes must each lock their storage).
0 = normal
non-zero = locked
Make sure the third-party application performs the following (in order):
1. Set lock_cmd to “1”.
2. Wait until lock_status is not zero.
3. Run snapshot.
4. Set lock_cmd to “2”.
IMPORTANT:  Do not alter any other table in the DS-System database.