[CentOS-devel] OT: os/ and kickstart/ seem identical on Centos 8?

Simon Matter

simon.matter at invoca.ch
Fri Sep 27 06:01:50 UTC 2019

> On Thu, 26 Sep 2019 at 05:29, Simon Matter via CentOS-devel
> <centos-devel at centos.org> wrote:
>> > On 26/09/2019 10:06, Kaj Niemi wrote:
>> >> Hi,
>> >>
>> >>
>> >> Is it on purpose that under AppStream, BaseOS, PowerTools (but not
>> under
>> >> extras, fasttrack and centosplusplus) there is an os and a kickstart
>> >> directory for each architecture? On a quick glance the directory
>> layout
>> >> and contents seem rather identical.
>> >>
>> >> Asking as “we” do a local mirror of releases and started wondering
>> about
>> >> the amount of disk space 8 takes.
>> >>
>> >
>> > Hi,
>> >
>> > kickstart is a snapshot of os at GA/release time.
>> > So that permits people to deploy with exactly same content without
>> > having a moving target, as BaseOS/AppStream will be including updates
>> as
>> > they land.
>> >
>> > WRT disk space, hopefully, as explained on how to mirror correctly
>> > (https://wiki.centos.org/HowTos/CreatePublicMirrors) , you use -H for
>> > rsync, as we heavily use hardlinks in our trees so that it reduces
>> space
>> > and also used bandwidth to sync mirror content
>> Hi,
>> I was just wondering why it wasn't implemented with symlinks? They have
>> the advantage that they can be recognized easily IMHO. You could then go
>> a
>> step further and even create an updates/ directory with only symlinks to
>> the corresponding files. It would allow to still have an updates/
>> directory which some of us are missing now.
> From dealing with mirroring issues a long time, large number of
> symlinks in a directory have broken various filesystems that various
> systems use. You end up with sites with missing symlinks, broken
> symlinks or other anomalies. If you hardlink the mirror might download
> the file twice but it will be there. If you symlink hundreds of files,
> you are debugging client issues to a mirror you don't control and you
> have to make your check script even more complicated to confirm that
> things are there versus just look to be there.

Interesting, I never saw issues with symlinks. Was it a problem with
filesystems or a problem with the sync tool?

A bit OT here but: I do have problems syncing large filesystems which
contain large number of hardlinks using rsync. I get the following error
and don't know how to go on. That's with rsync -aH:

building file list ... ERROR: out of memory in hashtable_node [sender]
rsync error: error allocating core memory buffers (code 22) at util.c(117)

I've built latest rsync to try but it fails the same way. Is the only way
to fix this to add more memory to the systems?


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