On 2011-03-31 15:47 John Rouillard wrote:
> The only way the March 30'th backup wouldn't have transferred the
> files was if the march 29th backup was a level 1 incremental and the
> march 30'th was a level 2 incremental. In that case the march 30'th
> incrementals reference tree would have been from the march 29 backup
> which already had the files in the new (moved) location and it would
> have been able to determine that the files were identical.
> Transfer decisions are based on the file names under the pc
> directory. If the file doesn't exist in the comparison tree (which is
> taken from the previous higher level backup for incrementals IIRC) it
> is transferred. Different names/path result in the file being
> transferred again.
> Pooling decisions are based on the checksums of the files that were
> transferred. Newly transferred files are checksummed and compared to
> files in the pool. So after the transfer occurred pooling should have
> happened and those newly transferred files would have been hardlinked
> into the pooled file.
John, I am having trouble reconciling what I see with your description. As
far as I know, I do only one level of incremental backups with a full
backup once a week. I see where backuppc is checking date stamps of the
incrementals against the last full backup. However, the backup data
transfer volumes suggest that the entire file is only transferred once. My
typical daily Internet bandwidth is around 300-500MB. The two 350MB files
were uploaded March 20th. The incremental backup on the next day bumped
my Internet usage to 1,480MB. The next day was also an incremental backup
but my Internet usage was only 480MB.
The incremental backup on March 29th bumped up my Internet usage to 990MB.
Even if backuppc decided it had to download the entire files because they
were in a different path, I would have expected that the incremental
backup on March 30th would have noticed that the files were already in the
pool. However, the Internet usage on March 30th was over 700MB when I
checked early in the morning. The full backup later that day 'got it
right' and only backed up 40MB.
I run a bunch of MediaWiki sites, all of which used the same code base but
each site installed the code in its own directory structure. My
recollection is that backuppc only physically transferred one set of code
files. The additional sites did not result in the same files being
transferred again, even though they were in different paths.
My suspicion is that backuppc gets confused if files were backed
up/excluded/unexcluded or backed up/moved. I will need to test out
various scenarios with tracing enabled, but won't get a chance for while.
Thanks, Norbert
------------------------------------------------------------------------------
Create and publish websites with WebMatrix
Use the most popular FREE web apps or write code yourself;
WebMatrix provides all the features you need to develop and
publish your website. http://p.sf.net/sfu/ms-webmatrix-sf
_______________________________________________
BackupPC-users mailing list
BackupPC-users@lists.sourceforge.net
List: https://lists.sourceforge.net/lists/listinfo/backuppc-users
Wiki: http://backuppc.wiki.sourceforge.net
Project: http://backuppc.sourceforge.net/
