Hi all, Rob, Andrea and Chris in particular,
Am 16.02.2026 um 23:01 schrieb Rob Gerber:
...
1. I ultimately used 'accurate = Mo3'. 'M' means "check mtime and
ctime". Anyone using this option should obviously select whichever hash
algorithm they specified in 'signature=xyz' (or probably 5 for the
default, md5).
the different hashing is a bit of a problem in my opinion, because we
should automatically adjust to use whatever hash we have in the catalog.
2. I was previously using 'accurate = yes' for this fileset. When I
changed the option to 'accurate = Mo3', this did not constitute a
fileset change that would trigger a new full backup (so you don't have
to turn on the potentially dangerous 'ignore fileset changes = yes' to
avoid provoking a new full backup).
I've been experimenting with the Accurate = o option recently, and had
somewhat mixed results. Also, I'm not 100% sure that I can predict what
happens when I restore a file which has only had attributes backed up,
not contents. Should all be safe, but I need to actually experiment, I
think.
3. I used the 'estimate' command to verify whether bacula was going to
do what I wanted, before running the job. Once I changed to use the
accurate 'o' flag, the estimate processes took a very long time, because
they had to hash all the files with changed metadata. I originally
thought I'd use something like 'accurate = pinso3'*(this didn't work!)*.
I suspect that, for your CIFS mount, the criteria
p for permissions,
i for inodes,
n number of links
are simply not working as those are not metadata CIFS provides with the
same semantics as POSIX.
The bacula manual said:
==================
accurate=<options> The options letters specified are used when running a
Backup
Level=Incremental/Differential in Accurate mode. *The options letters
are the same
as in the verify= option below with the addition of the following options:*
==================
I believed that 'accurate = pinso3' would work. It did not.
Ms3o is what I would use, and by the way, the signature should only be
used if actually necessary, i.e. a size change would trigger a backup of
the file data even before the signature is calculated. At least that's
my recollection from a while ago.
The bacula director did not throw an error when I reloaded the config,
BUT an estimate said I would have 100TB of files to back up, which tells
me it did not work correctly. It did take several days to estimate, so I
think it hashed the files.
Reasonable conclusion :-)
I changed the option to 'accurate = Mo3', and ran the estimate again.
This time, bacula thought it would have to back up 30TB of files. This
is the result I expected. I didn't check before making the mtime changes
to my files, but it's pretty plausible that we could have had 30TB of
new files on disk waiting for a backup.
4. Please note that in bconsole, the estimate command defaults to
level=full. You need to specify level=incremental in order to see
comparisons of how much data would be backed up in an incremental backup.
5. Eric posted some text from the manual about the 'accurate' 'o'
feature. Towards the end he said "This feature will be available in the
next 17.0 that is still cooking in our lab." 'Accurate = Mo3' is
definitely working in bacula 13.x. I think right now the only options
supported by this feature are 'M' or maybe 'mc' before 'o(hash
algorithm). I think he means that bacula CE 17.x will support more
expanded options like ’pinug2o’, not that the feature doesn't work at
all in bacula CE right now.
I believe there was some work done in this respect recently -- you could
probably call it a bug fix, and Eric probably thought more about his
goal than what he's starting from :-)
I hope this helps.
this is definitely something where a more thorough documentation
including examples / use cases would be helpful, too. But let's see what
we get with version 17 and then we make it shiny by adding a manual
chapter ;-)
In any case, thanks for sharing your experience!
Cheers,
Arno
Regards,
Robert Gerber
402-237-8692
[email protected] <mailto:[email protected]>
--
Arno Lehmann
IT-Service Lehmann
Sandstr. 6, 49080 Osnabrück
_______________________________________________
Bacula-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bacula-users
