Administrative Processes
Creation Date: April 29, 1997
Revision Date: October 04, 2011
Product: DS‑Client
Summary
The DS‑Client software has been designed for unattended operation, which is both self‑tuning and self‑maintaining. To accomplish these tasks, DS‑Client performs regular administrative processes. These processes clean, tune and backup the DS‑Client database, create statistical data, and verify backup sets with the DS‑System's actual online storage.
Types of Administrative Processes
Type | Description |
Local | Performs activities that do not require a connection to the DS‑System. This type of administrative process is always performed and cannot be disabled. (A Local Admin runs every time that the DS‑Client starts, once every 12 hours since the previous Admin, or every 24 hours.) |
Daily | Performs all Local activities (see above), a verification of backup sets (see Detailed Activities below) and transfers the DS‑Client database dump to the DS‑System. A Daily Admin process can be disabled or configured to run at a specific time (Setup > Configuration > Parameters). |
Weekly | Performs all Daily activities and a low‑level synchronization of backup sets (see below). A Weekly Admin process can be disabled or configured to run at a specific date and time (Setup > Configuration > Parameters). |
Configuration and Scheduling of Administrative Processes
Default Configuration
The default administrative configuration (which can be changed from Setup > Configuration > Parameters) will have the following settings:
• The Daily Admin process is scheduled to run once every day between 8PM and 6AM. (See note below.)
• The Weekly Admin process is scheduled to run once a week between 8PM Friday and 6AM Monday. (See note below.)
NOTE: To distribute the Administrative Process load from many DS-Clients, the exact (default) start time is randomly determined with an algorithm based on the DS-Client number, which results in a time that is some interval of 15 minutes (e.g. 9:30 or 01:45).
Automated reboot
An automated system reboot can be performed after the admin process. By default, this option is turned off, but can be reconfigured (Setup > Configuration > Parameters). It is recommended that this option be turned on if the DS‑Client computer performs unattended scheduled backups and does not normally shut down. This will refresh computer resources and memory leaks (if any have occurred).
Execution of Administrative processes
No other activities (backup, restore, etc.) are allowed while an Admin process executes. Therefore, any demand activity will be rejected. If an activity is executing at the time the admin process is scheduled, the admin process will wait for all activities to terminate.
During this time (waiting for activities to terminate) new activities can still be executed. Therefore it is possible that the scheduled Admin process never gets the opportunity to run (i.e. in the unlikely event that you have scheduled backups that run 24hrs/7days a week).
Who should perform Administrative processes?
It is recommended that you schedule the DS‑Client to perform Daily and Weekly administrative processes wherever possible for all DS‑Client configurations (i.e. Typical or Custom installation on LANs as well as on Standalone PCs). If it is not possible to schedule Admin processes, you should manually execute a Daily or Weekly Admin occasionally (Setup Menu > System Activities Administration dialog).
Administrative Process Activities Description
Activities Matrix
The following table shows administrative activities in the order that they are performed, and the administrative processes that perform them. The DS‑System column indicates whether a connection to the DS‑System is required for that activity.
Activity | Local | Daily | Weekly | DS‑System |
1. Prepare database dump | X | X | X | |
2. Clean database | X | X | X | |
3. Update statistical data | X | X | X | |
4. Expand database (if necessary) | X | X | X | |
5. Verify backup sets | | X | X | X |
6. Transfer database dump | | X | X | X |
7. Synchronization (Normal) | | | X | X |
8. Send daily email notification | X | X | X | |
Detailed Activities Description
1. Prepare database dump.
[Microsoft SQL Server] This activity depends on the option selected for Keep DS-Client database dump file (Setup > Configuration > Parameters):
• [Do not delete] Save the previous dump, dump the DS‑Client database and dsdelta database, run database consistency checks (DBCC). If a fatal error occurs, restore the previous dump, otherwise the previous dump will be deleted and only the current dump will remain in the DS-Client buffer.
• [Delete after successful backup] Save the previous dump (if it exists). Dump the DS‑Client database and dsdelta database, run database consistency checks (DBCC). If no errors occur, remove the previous database dump (if it exists) from the DS-Client buffer before connecting to the DS-System. If step 6 (Transfer Database Dump) is successful, then remove the current DS-Client database dump from the DS-Client buffer.
• [Always delete] Dump the DS‑Client database and dsdelta database, run database consistency checks (DBCC). After the Daily/Weekly Admin process is finished, delete the database dump.
• [PostgreSQL] This step is not performed.
2. Clean the databases:
• Delete old history logs (activities, events and statistics), drop unused tables and delete unused records.
3. Update statistical data:
• Update statistical information for each backup set (number of files and online amount).
• Update statistical information used by the storage summary.
4. Expand database (if necessary).
[Only applies to the free Microsoft SQL Server Express versions (2005, 2008 and 2008 R2). This step is not performed for full (purchased) Microsoft SQL Servers.]
• If DS-Client database is above its DBHighWaterMark parameter (DS-User: Setup > DS-Client Configuration > Advanced), expand the database by creating a new, sequential “expand<nnnn>” database.
• Move backup set(s) from the database that is over its high water mark into the new expanded database. This is done sequentially, starting with the largest backup set, until the database falls below the high water mark.
• [PostgreSQL] This step is not performed.
5. Verify backup sets.
• Send a list of all backup sets to the DS‑System. The DS‑System will send back a list of backup sets that either do not exist on the DS‑System's disk or exist on the DS‑System's disk but were not included in the DS‑Client's list.
• Update the information needed to recover backup sets falling into category 'b'.
6. Transfer database dumps.
• [Microsoft SQL Server] Transfer database dumps to DS‑System if Activity 1 was performed successfully.
• [Microsoft SQL Server] Delete database dumps if Activity 1 (b) or (c) was selected (from Setup > Configuration > Parameters).
• [PostgreSQL] Instead of transferring a dump, the database is backed up via Pipe to DS-System.
7. Synchronization (Normal).
• Perform synchronization check for all backup sets that are not in category 'a' or 'b' of Activity 5. (Note this is the same as a 'Normal' synchronization. However, any synchronized files will retain an 'active' backup status.)
8. Send daily email notification.
If the DS‑Client is configured for email notifications with Daily Notification on, a summary of backup activities will be sent to the administrator, showing a summary of what occurred since the last admin process.
Database Dump method (Microsoft SQL Server)
To speed up the Daily Admin process, Windows DS-Client uses differential backups if a full database dump exists on the DS-System. A differential backup creates a copy of all the pages in a database modified since the last full database backup.
During Weekly Admin, DS-Client will always perform a full database dump.
If Weekly Admin is disabled, a full database dump is performed during Daily Admin every 6 days (the full backup rotates the day on which it occurs).
The database dump of dsclient and dsdelta will be composed of the following:
• xxxxxxxxxxxx.dmp (full backup)
• xxxxxxxxxxxx_diff.dmp (differential backup)
• dsdelta.dmp (full backup)
• dsdelta_diff.dmp (differential backup)