Sorry for the delay here, I was hoping I would be able to reproduce this but after many attempts I don't see that much of a difference between sparse and non-sparse. Nevermind, the patch for setting up custom sparse-block size is in the upstream repo, only it is in the sort-of-unsupported rscyn-patches. I think it is ok to introduce this as a downstream change since this does not change any default usage and only for users who want to exploit the functionality could this feature make a difference.

I have a suspicion this causes a regression when using rsync with this patch applied against an rsync daemon that doesn't support the --sparse-block option, see https://pagure.io/centos-infra/issue/872.

This change breaks compatibility with older version of rsync. Running rsync from CentOS 8 stream to CentOS 7 is not possible without special parameters.

Versions of components:
rsync-3.1.3-16.el8.x86_64
rsync-3.1.2-10.el7.x86_64

What happens when trying to rsync:
[backuppc@backup ~]$ rsync -vvvv root.sk:/etc/hosts /tmp/test/
cmd=<NULL> machine=devel.xxxx.sk user=root path=/etc/hosts
cmd[0]=ssh cmd[1]=-l cmd[2]=root cmd[3]=devel.xxxx.sk cmd[4]=rsync cmd[5]=--server cmd[6]=--sender cmd[7]=-vvvve.LsfxC cmd[8]=--sparse-block=1024 cmd[9]=. cmd[10]=/etc/hosts
opening connection using: ssh -l root devel.xxxx.sk rsync --server --sender -vvvve.LsfxC --sparse-block=1024 . /etc/hosts  (11 args)
msg checking charset: UTF-8
rsync: on remote machine: --sparse-block=1024: unknown option
rsync error: syntax or usage error (code 1) at main.c(1568) [server=3.1.2]
rsync: connection unexpectedly closed (0 bytes received so far) [Receiver]
[Receiver] _exit_cleanup(code=12, file=io.c, line=226): entered
rsync error: error in rsync protocol data stream (code 12) at io.c(226) [Receiver=3.1.3]
[Receiver] _exit_cleanup(code=12, file=io.c, line=226): about to call exit(12)

It is possible to workaround this problem by adding --sparse-block=0 to rsync parameters, but this is too complicated and breaks some backup programs.

Please, revert this change. Also doesn't help to update rsync on CentOS 7, because there are other distributions, which can use rsync without this parameter.

I did not notice that this option is sent to the server every time. I am now working on a fix.

We (CentOS infra team) also confirm that we're suffering from that issue too, and that impacts the proper mirror workflow for CentOS Stream 8 and 9.
Can that package be removed from CentOS Stream 8 for the time being ?

+1 also affected

I can confirm this behaviour.

CentOS Stream 8, rsync local 3.1.3-16

Without having set the opsion --sparse-block, I get this nonetheless:

rsync: on remote machine: --sparse-block=1024: unknown option
rsync error: requested action not supported (code 4) at clientserver.c(1556) [Receiver=3.0.9]
rsync: read error: Connection reset by peer (104)
rsync error: error in socket IO (code 10) at io.c(785) [sender=3.1.3]

adding info as i don't see it on the BZ already

this is hitting tripleo image build jobs on centos8 - upstream bug at https://bugs.launchpad.net/tripleo/+bug/1984035

workaround for now is to downgrade rsync to 3.1.3-14 https://review.rdoproject.org/r/c/config/+/44471

Hi,

I am putting this here as a public comment - we know about the issue and the fix is already out - rsync-3.1.3-17.el8. You can either downgrade to rsync-3.1.3-15.el8 where the feature is not present or wait till the -17 version gets to the CentOS.

build: https://brewweb.engineering.redhat.com/brew/buildinfo?buildID=2114622

I know this affects a lot of systems, no need to add more and more systems that are affected here as comments.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (Moderate: rsync security and enhancement update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2022:7793