Thanks Colin & Jacob.
With several hundred Gb's of data being archived, the local tarbell
option is probably not going to work for me.
Does "tarsnap -t -f" show file modification date based on what the
filesystem is reporting, on when tarsnap detects a change?
To provide more details, I had a number of sectors on an SSD silently
faile so I needed to identify and restore files that were corrupted by
this evemt. The filesystem did not report any change in modification
date on these files, so couldn't rely on this to identify which files to
restore. Hence my question around reporting on the files impacted by
block changes between archives, to both identify an expected change, and
recover from this.
If tarsnap can't do this, perhaps I need to start capturing a hash of
each file at the time of backup, and compare those between archives.
Cheers,
Scott
On 19/6/19 7:15 am, Jacob Larsen wrote:
I had the same issue a while back. I was told it was not easily fixed
due to the layers in Tarsnap. I ended up making a regular tarball and
fed that to tarsnap. That way I had a local tarball that matched the
actual data in the archive. Then I could extract it and compere at the
next backup. A bit data heavy process but it gave me what I needed. It
is scriptable, so it is possible to let your backup script log the
changed files on each backup run, but it has a pretty high cost in
disk I/O, plus you need to keep a copy of your data around between
backups.
/Jacob
On 18/06/2019 13.49, Scott Dickinson wrote:
Hi,
I'm trying to work out how to generate a report on files that are new
or changed in a particular archive. I can't seem to find an easy way
to do this, so hoping someone can help.
Here is the scenario I'm working through.
1. Backup directory "x" on 1st May 2019. First time archive, all 10Gb
are sent as expected.
2. Backup directory "x" on 1st June 2019. Second time archive, 25Mb
are sent.
How can I report on which files that 25Mb of delta's are part of? In
this scenario, I wasn't expecting any changes to the files over the
month, so am surprised there were anything above the metadata to be
backed up. My understanding is that Tarsnap needs to know which files
the changed blocks belong to, therefore in theory this metadata
should be extractable.
The closest I've found to locate this is "tarnsap -t -f 'x' -v
--iso-dates", but this doesn't natively provide the details I'm
after. Ideally I'd like tarsnap to be able to report which files were
uploaded at the time or archive with an option similar to --print-stats.
Anyone got any ideas?
Cheers,
Scott