On 16.07.2019 08:30, Andreas Rogge wrote:
"By turning on the *sparse* option, Bareos will specifically look for
empty space in the file, and any empty space will not be written to the
Volume, nor will it be restored."
(https://docs.bareos.org/Configuration/Director.html#fileset-resource
)Sorry. My bad.
The docs is correct. Bareos will puch a hole during restore if the
sparse option was set in the backup fileset.
The misleading behaviour was that this is done whether or not the
original file was actually sparse or just contained regions of 32K
contigous zeros.
You're getting me confused now :-)
First you wrote that fd doesn't write the file as sparse when restoring.
Now you say that fd "punches a hole" which - IMHO - suggests creating a
sparse file.
Maybe it's a matter of wording but in this context "punch a hole" I'd
interpret as creating a "holed" file. Which suggests strongly a sparse file.
I understand of course that sparsiness logic just looks for contiguous
regions of zeroes (do they need to be aligned to 32k boundary or do they
need to just be contiguous 32k zeros, BTW?).
But from what I understood from writing the sparse option description
(and I believe the original poster inferred the same) was that if the
sparse option is set, the fd looks for blocks of zeroes (regardless of
whether the file is indeed a sparse file on the underlying filesystem or
is just a plain fully-alocated file filled with zeros), writes the file
as sparse to the sd and then on restore creates a "holed" file without
those zeroed blocks. Which, for me, meant sparse.
It's a bit confusing since indeed the word "sparse" can be understood
differently on different levels so maybe it's worth to add a word or two
to the docs that the sparsiness of the backup is meant only in regard to
the method of storing the backup on backup media, not to the sparsiness
of the file itself in terms of the underlying filesystem?
--
You received this message because you are subscribed to the Google Groups
"bareos-users" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/bareos-users/baa659fb-ea24-2d48-825c-bcefaabdcfd6%40gmail.com.
For more options, visit https://groups.google.com/d/optout.
