How many online probkups can be taken?

PROBKUP has a limit of 16 million online backups:

• The logic in backup has been changed for Type I Storage Areas to work with this limitation.
• The first full backup in OpenEdge 12 will set the backup counters appropriately.
• The command to enable this feature is no longer functional in OpenEdge 12, as this feature is enabled by default and is no longer listed in the DB Features report.

• The Backup Counter Extension feature must first be manually enabled offline before the backup counter overflow
• Once the extended backup counter feature is enabled, the next backup is required to be a full backup in order that the new update counters are initialised in every database block to support this feature. 

• This feature will only be seen in OpenEdge 11.7.5+ Database Features Reports
• If an OpenEdge 11.7.5+ database has this feature enabled, migrating to OpenEdge 12 with conv1112 removes the feature bit, because the underlying code and functionality are always on and no is longer displayed in the Database Features Report

Database Features
   ID   Feature                            Active  Details
  ----  ---------------------------------  ------  -------
...
    28  Backup Counter Extension           Yes

PROBKUP has a limit of 65535 online backups:

Prior to OpenEdge 11.7.5, 12.0, the backup counter stored in the database Master Block is 2 bytes which has a maximum value of 65535 . 

• This backup counter is incremented in the Database Master Block every time a PROBKUP is run (online, offline; full, incremental).
• The inevitable end result of databases that are backed up frequently over a number of years, is that this counter will overflow once reached. As a consequence, all necessary blocks in the database will not be included in the online backup volume(s).
• For example, if one PROBKUP is taken every hour (online/offline/incremental), the counter will overflow in ~7 years. 

What happens when the backup counter overflows?

1. The logic which determines if a block should be backed up in an online backup routine, will not consider existing data blocks to be included as their backup counters are higher than the overflow value stored in the master block backup counter. The online backup will initially only backup 'new' database blocks that have never been backed up (ie empty blocks that have been formatted) and from that point on, these database blocks if they qualify and 'new' database blocks resulting in an invalid backup volume.
2. The offline backup logic is different and is therefore not affected by the backup counter overflow. In other words, an offline PROBKUP will be complete and a full restored database will result, but subsequent online PROBKUP of this restore will suffer the same online backup counter overflow logic.

How to reset database block backup counters?

1. Upgrade to OpenEdge 11.7.5+ and enable the Backup Counter Extension feature
2. Migrate to OpenEdge 12+ with conv1112 and run a full backup. The first backup after enabling the feature or conv1112 is enforced to be a full probkup.

• Backup counters in the database blocks are reset to 0 after a dump and load.

1. move tables and indexes with PROUTIL -C tablemove/indexmove
2.  move LOBS with buffer-copy ABL code
3. This includes using 'PROUTIL -C mvsch', to re-initialise the Schema Area and eventually remove the "Old Default Area".

• Truncate the Schema Area with PROUTIL mvsch       
• How to move a LOB to another Storage Area?

Until database block backup counters can be reset:

An alternative backup strategy needs to be engineered, Options include:

• Offline PROBKUP
• Online OS copy (with PROQUIET on Enterprise databases)
• AI Rollforward from the last restored probkup volume before counters overflowed or using the offline backup to apply ai notes.
• OpenEdge Replication Target database online PROBKUP (available since OpenEdge 10.1C), if the backup counter on the target has not overflowed.

How to determine the current backup counter value ?

1. If the backup counter has overflowed, the database must be re-set as outlined above. It is not sufficient to simply enable the Backup Counter Extension feature
2. In OpenEdge 11.7.5, the Backup Counter Extension feature must be manually enabled offline before the counter overflow, followed by a full PROBKUP

OpenEdge 10,11: To verify the current backup counter value

$  proutil dbname -C truncate bi
$  proutil dbname -C dbrpr

Schema Area (6)  
Extent 1  
Block 2 ----------- 0000 
bk_dbkey:     0x00000020         32      
bk_type:      0x01               1 (Master Block)      
bk_frchn:     0x7f               127 (NOCHN) **   
bk_incr:      0xFC92             64658

Progress 9 : To verify the current backup counter value

The DBRPR Menu Options above are not available in Progress 9. The Master Block needs to be dumped with DBRPR and analysed:

• The backup counter value is on the first line offset: 06-07

1. The database Master Block for a multi-volume database is the second physical block of the first data extent (Schema Area).

• Identify if the Schema Area has 32 or 64 records per blocks (RPB) from the database structure with "prostrct list <dbname>" 

2. Use DBRPR to dump the Master Block from the Schema Area (6).

By default the DBRPR tool starts in the Schema Area: Current Working Area: Schema Area

The Master Block is the first Block in this Area:

• If the Schema Area is 32 RPB then the dbkey for the master block is 32
• If the Schema Area is 64 RPB then dbkey for the master block is 64.

$  proutil dbname -C truncate bi
$  proutil <dbname> -C dbrpr <dump.in> /dev/null 2>&1

4
<Substitute with 32 or 64 depending on the RPB value>
q

>0000    4000 0000 017F FDFE 0000 0000 0000 00E6
------------------------^^^^

>0000    4000 0000 017F FEFD 0000 0000 00E6 0000
------------------------^^^^

Other indicators that the backup counter has overflown: