[tahoe-lafs-trac-stream] [Tahoe-LAFS] #755: Allow deep-check to continue after error, and: if there is an unrecoverable subdirectory, the deep-check report (both WUI and CLI) loses other information

[Tahoe-LAFS]

#755: Allow deep-check to continue after error, and: if there is an unrecoverable
subdirectory, the deep-check report (both WUI and CLI) loses other
information
-------------------------+-------------------------------------------------
     Reporter:  zooko    |      Owner:  daira
         Type:  defect   |     Status:  new
     Priority:           |  Milestone:  soon
  critical               |
    Component:  code-    |    Version:  1.4.1
  dirnodes               |   Keywords:  usability error tahoe-check wui
   Resolution:           |  verify repair
Launchpad Bug:           |
-------------------------+-------------------------------------------------

Comment (by tlhonmey):

 Kyle:  It won't have to re-upload all the healthy files.  The
 deduplication algorithm will find that the data for any unchanged files is
 already available and will re-use whatever shares it can.  It'll just take
 a bit longer to run because it'll have to scan and encode every file.


 Meanwhile:  I just lost a bunch of stuff because I didn't know about this
 issue and assumed a deep-check --repair --add-lease cronjob would take
 care of things.  One file near the beginning of the directory structure
 got damaged somehow, so neither repair nor leasing was done on the rest,
 and by the time I came back to check on it, chunks had expired and been
 deleted and I have to re-upload everything, which will take about a month.

 This bug has been open for almost 8 years, and I see a patch for it in the
 discussion thread...  If it's not going to be fixed in the next release, I
 recommend adding a warning about it to the documentation so new users
 don't do something stupid like expect the repair operation to behave in a
 sane manner.


 As a work-around, I use:
 {{{
 tahoe manifest alias: | cut -d" " -f 1 | xargs -L1 -P5 tahoe check --add-
 lease --repair
 }}}

 This, of course, requires time and CPU to start a separate instance of the
 tahoe program for every data object being checked, so going over the
 entire directory takes days instead of hours, but at least it actually
 works.

--
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/755#comment:38>
Tahoe-LAFS <https://Tahoe-LAFS.org>
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