<div dir="ltr"><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Sep 18, 2020 at 7:51 AM Matthew Knepley <<a href="mailto:knepley@gmail.com">knepley@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div dir="ltr">On Fri, Sep 18, 2020 at 7:46 AM Mark Adams <<a href="mailto:mfadams@lbl.gov" target="_blank">mfadams@lbl.gov</a>> wrote:<br></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Oh you did not change my hostname:<div><br></div><div>07:37 master *= ~/Codes/petsc$ hostname<br>MarksMac-302.local<br>07:41 master *= ~/Codes/petsc$ ping -c 2 MarksMac-302.local<br>PING marksmac-302.local (127.0.0.1): 56 data bytes<br>Request timeout for icmp_seq 0<br><br>--- marksmac-302.local ping statistics ---<br>2 packets transmitted, 0 packets received, 100.0% packet loss<br>07:42 2 master *= ~/Codes/petsc$</div></div></blockquote><div><br></div><div>This does not make sense to me. You have</div><div><br></div><div> 127.0.0.1 MarksMac-302.local</div><div><br></div><div>in /etc/hosts, </div></div></div></blockquote><div><br></div><div>09:07 ~/.ssh$ cat /etc/hosts<br>##<br># Host Database<br>#<br># localhost is used to configure the loopback interface<br># when the system is booting. Do not change this entry.<br>##<br>127.0.0.1 localhost<br>255.255.255.255 broadcasthost<br>127.0.0.1 MarksMac-5.local<br>127.0.0.1 <a href="http://243.124.240.10.in-addr.arpa.private.cam.ac.uk">243.124.240.10.in-addr.arpa.private.cam.ac.uk</a><br>127.0.0.1 MarksMac-302.local<br>09:07 ~/.ssh$<br><br></div><div><br></div><div><br></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div class="gmail_quote"><div>but you cannot resolve that name?</div><div><br></div><div> Matt</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>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.</div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Sep 17, 2020 at 11:10 PM Satish Balay via petsc-users <<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On Thu, 17 Sep 2020, Matthew Knepley wrote:<br>
<br>
> On Thu, Sep 17, 2020 at 8:33 PM Barry Smith <<a href="mailto:bsmith@petsc.dev" target="_blank">bsmith@petsc.dev</a>> wrote:<br>
> <br>
> > > On Sep 17, 2020, at 4:59 PM, Satish Balay via petsc-users <<br>
> > <a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>> wrote:<br>
> > ><br>
> > > Here is a fix:<br>
> > ><br>
> > > echo 127.0.0.1 `hostname` | sudo tee -a /etc/hosts<br>
> ><br>
> > Satish,<br>
> ><br>
> > I don't think you want to be doing this on a Mac (on anything?) On a<br>
> > Mac based on the network configuration etc as it boots up and as networks<br>
> > are accessible or not (wi-fi) it determines what hostname should be, one<br>
> > should never being hardwiring it to some value.<br>
> ><br>
> <br>
> Satish is just naming the loopback interface. I did this on all my former<br>
> Macs.<br>
<br>
<br>
Yes - this doesn't change the hostname. Its just adding an entry for gethostbyname - for current hostname.<br>
<br>
>>><br>
127.0.0.1 MarksMac-302.local<br>
<<<<br>
<br>
Sure - its best to not do this when one has a proper IP name [like <a href="http://foo.mcs.anl.gov" rel="noreferrer" target="_blank">foo.mcs.anl.gov</a>] - but its useful when one has a hostname like "MarksMac-302.local" -that is not DNS resolvable<br>
<br>
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]<br>
<br>
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]<br>
<br>
<br>
Satish<br>
</blockquote></div>
</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>-- Norbert Wiener</div><div><br></div><div><a href="http://www.cse.buffalo.edu/~knepley/" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><br></div></div></div></div></div></div></div></div>
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