> >> 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] 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 <knep...@gmail.com> wrote: > > > On Fri, Sep 18, 2020 at 7:46 AM Mark Adams <mfad...@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@mcs.anl.gov> wrote: > >> > >>> On Thu, 17 Sep 2020, Matthew Knepley wrote: > >>> > >>> > On Thu, Sep 17, 2020 at 8:33 PM Barry Smith <bsm...@petsc.dev> wrote: > >>> > > >>> > > > On Sep 17, 2020, at 4:59 PM, Satish Balay via petsc-users < > >>> > > petsc-users@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/> > > >
