[petsc-users] osx error

Fri Sep 18 10:05:36 CDT 2020

On Fri, Sep 18, 2020 at 11:04 AM Satish Balay <balay at mcs.anl.gov> wrote:

> On Fri, 18 Sep 2020, Satish Balay via petsc-users wrote:
>
> > > >> 07:41 master *= ~/Codes/petsc$ ping -c 2 MarksMac-302.local
> > > >> PING marksmac-302.local (127.0.0.1): 56 data bytes
> >
> > So it is resolving MarksMac-302.local as 127.0.0.1 - but ping is not
> responding?
> >
> > I know some machines don't respond to external ping [and firewalls can
> block it] but don't really know if they always respond to internal ping or
> not.
> >
> > If some machines don't respond to internal ping  - then we can't use
> ping test in configure [it will create false negatives - as in this case]
>
> BTW: To confirm, please try:
>
> ping 127.0.0.1
>

11:02 master *= ~/Codes/petsc$ sudo vi /etc/hosts
11:02 master *= ~/Codes/petsc$ ping 127.0.0.1
PING 127.0.0.1 (127.0.0.1): 56 data bytes
Request timeout for icmp_seq 0
Request timeout for icmp_seq 1
Request timeout for icmp_seq 2
Request timeout for icmp_seq 3
Request timeout for icmp_seq 4
Request timeout for icmp_seq 5
Request timeout for icmp_seq 6
Request timeout for icmp_seq 7
Request timeout for icmp_seq 8
Request timeout for icmp_seq 9
Request timeout for icmp_seq 10
Request timeout for icmp_seq 11
Request timeout for icmp_seq 12
Request timeout for icmp_seq 13
Request timeout for icmp_seq 14
Request timeout for icmp_seq 15
Request timeout for icmp_seq 16
Request timeout for icmp_seq 17
Request timeout for icmp_seq 18
Request timeout for icmp_seq 19
Request timeout for icmp_seq 20
Request timeout for icmp_seq 21

still going ......

>
> Satish
>
> >
> >
> > Mark, can you remove the line that you added to /etc/hosts - i.e:
> >
> > 127.0.0.1 MarksMac-302.local
> >
> > And now rerun MPI tests. Do they work or fail?
> >
> > [this is to check if this test is a false positive on your machine]
> >
> > Satish
> >
> >
> > On Fri, 18 Sep 2020, Mark Adams wrote:
> >
> > > On Fri, Sep 18, 2020 at 7:51 AM Matthew Knepley <knepley at gmail.com>
> wrote:
> > >
> > > > On Fri, Sep 18, 2020 at 7:46 AM Mark Adams <mfadams at lbl.gov> wrote:
> > > >
> > > >> Oh you did not change my hostname:
> > > >>
> > > >> 07:37 master *= ~/Codes/petsc$ hostname
> > > >> MarksMac-302.local
> > > >> 07:41 master *= ~/Codes/petsc$ ping -c 2 MarksMac-302.local
> > > >> PING marksmac-302.local (127.0.0.1): 56 data bytes
> > > >> Request timeout for icmp_seq 0
> > > >>
> > > >> --- marksmac-302.local ping statistics ---
> > > >> 2 packets transmitted, 0 packets received, 100.0% packet loss
> > > >> 07:42 2 master *= ~/Codes/petsc$
> > > >>
> > > >
> > > > This does not make sense to me. You have
> > > >
> > > >   127.0.0.1 MarksMac-302.local
> > > >
> > > > in /etc/hosts,
> > > >
> > >
> > > 09:07  ~/.ssh$ cat /etc/hosts
> > > ##
> > > # Host Database
> > > #
> > > # localhost is used to configure the loopback interface
> > > # when the system is booting.  Do not change this entry.
> > > ##
> > > 127.0.0.1 localhost
> > > 255.255.255.255 broadcasthost
> > > 127.0.0.1    MarksMac-5.local
> > > 127.0.0.1 243.124.240.10.in-addr.arpa.private.cam.ac.uk
> > > 127.0.0.1 MarksMac-302.local
> > > 09:07  ~/.ssh$
> > >
> > >
> > >
> > >
> > >
> > > > but you cannot resolve that name?
> > > >
> > > >   Matt
> > > >
> > > >
> > > >> BTW, I used to get messages about some network issue and 'changing
> host
> > > >> name to MarksMac-[x+1].local'. That is, the original hostname
> > > >> was MarksMac.local, then I got a message about changing
> > > >> to MarksMac-1.local, etc. I have not seen these messages for months
> but
> > > >> apparently this process has continued unabated.
> > > >>
> > > >>
> > > >>
> > > >>
> > > >>
> > > >>
> > > >>
> > > >>
> > > >>
> > > >> On Thu, Sep 17, 2020 at 11:10 PM Satish Balay via petsc-users <
> > > >> petsc-users at mcs.anl.gov> wrote:
> > > >>
> > > >>> On Thu, 17 Sep 2020, Matthew Knepley wrote:
> > > >>>
> > > >>> > On Thu, Sep 17, 2020 at 8:33 PM Barry Smith <bsmith at petsc.dev>
> wrote:
> > > >>> >
> > > >>> > > > On Sep 17, 2020, at 4:59 PM, Satish Balay via petsc-users <
> > > >>> > > petsc-users at mcs.anl.gov> wrote:
> > > >>> > > >
> > > >>> > > > Here is a fix:
> > > >>> > > >
> > > >>> > > > echo 127.0.0.1 `hostname` | sudo tee -a /etc/hosts
> > > >>> > >
> > > >>> > >  Satish,
> > > >>> > >
> > > >>> > >    I don't think you want to be doing this on a Mac (on
> anything?)
> > > >>> On a
> > > >>> > > Mac based on the network configuration etc as it boots up and
> as
> > > >>> networks
> > > >>> > > are accessible or not (wi-fi) it determines what hostname
> should be,
> > > >>> one
> > > >>> > > should never being hardwiring it to some value.
> > > >>> > >
> > > >>> >
> > > >>> > Satish is just naming the loopback interface. I did this on all
> my
> > > >>> former
> > > >>> > Macs.
> > > >>>
> > > >>>
> > > >>> Yes - this doesn't change the hostname. Its just adding an entry
> for
> > > >>> gethostbyname - for current hostname.
> > > >>>
> > > >>> >>>
> > > >>> 127.0.0.1 MarksMac-302.local
> > > >>> <<<
> > > >>>
> > > >>> Sure - its best to not do this when one has a proper IP name [like
> > > >>> foo.mcs.anl.gov] - but its useful when one has a hostname like
> > > >>> "MarksMac-302.local" -that is not DNS resolvable
> > > >>>
> > > >>> Even if the machine is moved to a different network with a
> different
> > > >>> name - the current entry won't cause problems [but will need
> another entry
> > > >>> for the new host name - if this new name is also not DNS
> resolvable]
> > > >>>
> > > >>> Its likely this file is a generated file on  macos  - so might get
> reset
> > > >>> on reboot - or some network change? [if this is the case - the
> change won't
> > > >>> be permanent]
> > > >>>
> > > >>>
> > > >>> Satish
> > > >>>
> > > >>
> > > >
> > > > --
> > > > What most experimenters take for granted before they begin their
> > > > experiments is infinitely more interesting than any results to which
> their
> > > > experiments lead.
> > > > -- Norbert Wiener
> > > >
> > > > https://www.cse.buffalo.edu/~knepley/
> > > > <http://www.cse.buffalo.edu/~knepley/>
> > > >
> > >
> >
>
>
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