aims team mailing list archive

[Robie Basak <1384503@xxxxxxxxxxxxxxxxxx>]

On Tue, Jan 03, 2017 at 05:00:09AM -0000, Haw Loeung wrote:
> rsync shipped in Xenial builds with the included zlib (--with-included-
> zlib=yes and -Izlib). Couldn't we SRU a fix doing the same thing as per
> https://bugs.launchpad.net/rsync/+bug/1300367/comments/6?

I am -1 on any SRU that does not come with a comprehensive regression
risk analysis. It's not the patch that is the problem; it is the
consideration of all interoperability permutations that needs to be made
if behaviour in this area is to be changed.

I'm not saying we can't do it; just that we need to carefully consider
what behaviour in what parts of the interoperability matrix we'd be
changing, what the regression risk is for each of those permutations,
and how to mitigate that.

It's not sufficient to say "we did it in Xenial so we can do the same in
Trusty". For example: without testing or analysis, I don't know if your
proposal breaks interoperability between Precise and Trusty when perhaps
that combination works today, or between non-updated Trusty and updated
Trusty.

My example is not exhaustive (testing just my example is not enough).

Remember also that each version combination has two directions, further
exploding the number of permutations to check. It would be OK if an
analysis convincingly collapses some of the permutations, but no such
analysis currently exists, AFAIK.

-- 
You received this bug notification because you are a member of AIMS,
which is subscribed to a duplicate bug report (1431709).
https://bugs.launchpad.net/bugs/1384503

Title:
  rsync fails on large files with compression

Status in rsync package in Ubuntu:
  Fix Released
Status in rsync source package in Trusty:
  Triaged

Bug description:
  [Status]
  This issue is currently Incomplete.

  We're currently blocked on obtaining access to a reliable, and publicly 
  available dataset that can be shared to reproduce the issue.  The test
  is critical to being able to evaluate the impact of the change on other
  users when assessing if the fix can be SRU'ed to trusty.

  If you are affected by this bug and can reliably reproduce the issue
  with a specific dataset that you are willing and permitted to share please
  comment and specify the dataset location, and how you reproduce the issue.

  
  [Original Description]
  Copying large (>10GB) files with rsync -z (compression) leads to a long hang and eventual error after transferring part of the file.  The error is consistent.  The file copies at normal speed until it reaches its maximum size (1.4 GB out of 20 GB for one, 6.9 GB out of 29 GB for another).  Then nothing happens for a while (many minutes).  Finally, there is an error:

  [....]
  jh/.VirtualBox/win7/win7.vbox
  jh/.VirtualBox/win7/win7.vbox-prev
  jh/.VirtualBox/win7/win7.vdi
  rsync: [sender] write error: Broken pipe (32)
  rsync error: error in rsync protocol data stream (code 12) at io.c(837) [sender=3.1.0]

  In this case, 6.9 GB of 29 GB transferred.  Without -z, it works.

  See the following upstream report, with a comment at the end from the
  rsync maintainer:

  https://bugzilla.samba.org/show_bug.cgi?id=10372

  According to this report, version 3.1.0 (included in 14.04) uses a
  different compression package from prior versions.  Prior versions did
  not have this problem for me using the same command on the same
  systems. Both hosts ran Ubuntu 11.10 at the time, and all run 14.04
  now, in each case with all updates applied, Intel hardware.  Network
  connection between them is gigabit ethernet through one switch.  A
  shell ssh between them in a terminal works and stays up during the
  failure, so it is not a network issue.  There are no relevant entries
  in syslog on either machine.  There is sufficient capacity on the
  receiving disk.  All filesystems are ext4.

  rsync command:

  /usr/bin/rsync -aHSxvz --delete --stats --exclude=lost+found
  --exclude=.gvfs --exclude=/nonlaptop /home/
  backup.host.edu:/bu/host/home/

  (yes, I changed the machine names)

  Current release (both hosts):

  Description:	Ubuntu 14.04.1 LTS
  Release:	14.04

  Current package (both hosts):

  rsync:
    Installed: 3.1.0-2ubuntu0.1
    Candidate: 3.1.0-2ubuntu0.1
    Version table:
   *** 3.1.0-2ubuntu0.1 0
          500 http://us.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
          500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
          100 /var/lib/dpkg/status
       3.1.0-2 0
          500 http://us.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages

  Thanks,

  --jh--

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