Hi Bob -

I regularly backup older multi-gigabyte PST files.  I use a 7 day Fill schedule.  BackupPC doesn't actually backup the file if it is unchanged, but it will appear in the backup # of the Filled backup.  I've messed with full backups and filled schedules.   It's all a wash - any pre-existing unchanged file isn't backed up - it simply appears in the backup #.

Craig stated the fulls and filled backups are de-coupled and it appears to be so.  

On 2017-06-02 22:24, Bob Katz wrote:

One of the hosts being backed up is a photographer's computer with a huge 7 TB store of photos. Many of the photos are multi-layer photoshop files some larger than a GB each. The vast majority of this storage is archival. Only a small percentage of photos are changing or being added to at any moment in time.

What would be the consequences of setting the backuppc parameters so this host never gets another full backup? The documentation speaks of an ever-increasing number of deltas and a tradeoff in speed.

If you do a Filled backup this will help with speed and the deltas.  So I do a Filled backup every 7 days.  Every new backup is Filled.

For such a host with many very large files and a very large file storage, what would be the optimum suggested settings for:

$Conf{FullPeriod}     --- which we want large enough to ensure we NEVER do another full backup

Why?  

$Conf{FillCycle}    --- if we set this >0 would it slow down the day-to-day backup operation?

With these very large files is there any issue with setting$Conf{FullKeepCnt}  >1   ?

Full keep count *seems* to correspond to the number of Filled backups kept around...

I'm not seeing any negative results with keeping FullPeriod at 6.97 and FillCycle at 7.

I must admit I'm confused by the documentation for $Conf{FullKeepCnt}:

"In the steady state, each time a full backup completes successfully the oldest one is removed. If this number is decreased, the extra old backups will be removed."

Does this still apply since "fullkeepcnt" in v4+ means "filledkeepcount"?

Expiration seems a little different but overall I am satisfied with performance and space consumption.

I have one particular system that gets backed up every hour - FillCycle is still 7, and FullPeriod is still 6.97.  So every 7 hours I get a filled backup.

A full backup takes 35 minutes for 500k plus files.  The filled backup takes 2 minutes and is still an incremental.

The most recent backup is always filled.  One way to check how the system works is you drill down in the most recent backup to a file you know hasn't changed for a very long time.  From the drop-down select an incremental, unfilled backup.  What you'll see is the file marked with the next filled backup.  You could be selecting #772 but the next closest filled backup is #776.  

As for expiration FullKeepCount *seems* to mean "FilledKeepCount".  I've done the math and it appears to be such.

It's late so I hope this makes a little sense.....

Thanks for any advice,

Bob Katz

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