Question: How does the new Selective Incremental Mode work? How do I implement?
Keywords: SI, selective incremental
Operating Systems: ALL

This new feature is available on LONE-TAR v4.4.x

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1. Enabling Selective-Incremental Mode for a device
2. How Selective-Incrementals work
3. Details on how the Increment date is generated
3. Flow-chart of SI Mode

Related Links:

Take a look at the CRONY Menu in greater detail
YouTube Video: How to setup a backup with LONE-TAR through CRON 'unattended'

 

Critical Notes

  • When enabling SI Mode, Selective backups will perform differently. Details below.


Enabling Selective-Incremental Mode for a device 

LONE-TAR ships with this feature disabled by default.

1. To change this setting from LONE-TAR Menu System

Type the command: # ltmenu
Select Option 9 (Device Manager)
Select Option 'E' to edit highlighted Device (Press ENTER to cycle through devices to edit)
Select Option 'Si' (Selective-Incrementals)

[ ACTIVE ]
Selective Backup files will look like: Si-backup-Mon.ltar All Selective backups will be based on date of Last MASTER for this device

[ DISABLED ]
Original Setting Selective Backup files will look like: S-backup-Mon.ltar All backups will be based on no date and backup inclusion list

2. You can also enable/disable this setting straight from the device library file /usr/lone-tar/ltar.dev

Type the command: # vi /usr/lone-tar/ltar.dev
Scroll down to the device you wish to edit.
Look for the Device Variable LTMasterDate[x]

If LTMasterDate[x]="1" then Selective-Incremental Mode is ACTIVE.

If LTMasterDate[x]="0" then Selective-Incremental Mode is DISABLED.

 

How Selective-Incrementals work 

What Selective-Incremental means is you are taking a Selective style backup with LONE-TAR and incrementing the files being backed up from the last Master Backup of that particular device.

So if you backup to a RDX Storage drive, and turn on Selective-Incremental Mode all the Selective backups to this device will be based on the LAST Successful Master Backup date for this device only. If no Master Backup has been successfully completed, then the Selective backup will backup all included files based on no date stamp.

The Incremental backup in previous versions of LONE-TAR would only backup changed files from the LAST Master backup. This became an issue when users would perform multiple backups locally and remotely, but want to Increment on individual times and not all the same time. This new feature allows to have multiple Incremental Backups for multiple devices.

Rotation Example with Selective-Incremental Mode enabled:
M-backup-Mon.ltar
Si-backup-Tue.ltar
Si-backup-Wed.ltar
M-backup-Thu.ltar
Si-backup-Fri.ltar

Rotation Example with Selective-Incremental Mode disabled:
M-backup-Mon.ltar
I-backup-Tue.ltar
I-backup-Wed.ltar
M-backup-Thu.ltar
I-backup-Fri.ltar

Both rotation schemes do the same exact thing. However the SI mode allows to do this for multiple devices rather than just one device.

Also, SI Mode allows you to selectively pick which directories you wish to backup incrementally.


So if you have a crash, all you have to restore is your most current LONE-TAR Master Backup and most current Selective-Incremental Backup. Simple.

 

Details on how the Increment date is generated.

When a Master Backup completes and bit-level verifies, LONE-TAR captures the date of the backup and posts the date to a file with the device number of the current backup device.

Filename example: /usr/lone-tar/Master-date-device4 ... /usr/lone-tar/Master-date-device#

Once Selective-Incremental Mode is enabled all selective backups for this device will look for that completion date and if that date exists, it will backup only the files that have been modified from that date and on.

 

New Device Manager Display Options