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<p class="MsoNormal"><span style="font-size:11.0pt">Sounds like a bug. What Lustre version is being used?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Chris Horn<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><b><span style="font-size:12.0pt;color:black">From:
</span></b><span style="font-size:12.0pt;color:black">John White <jwhite@lbl.gov><br>
<b>Date: </b>Wednesday, March 5, 2025 at 5:48</span><span style="font-size:12.0pt;font-family:"Arial",sans-serif;color:black"> </span><span style="font-size:12.0pt;color:black">PM<br>
<b>To: </b>Horn, Chris <chris.horn@hpe.com><br>
<b>Cc: </b>lustre-discuss@lists.lustre.org <lustre-discuss@lists.lustre.org><br>
<b>Subject: </b>Re: [lustre-discuss] multi-hop routing<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:11.0pt">Just a quick follow-up for posterity, I did seem to need to add a route for tcp to the server-side. lctl ping was working but MGS communication was failing saying it couldn’t
talk back to the router:<br>
[Wed Mar 5 15:28:26 2025] LNetError: 28576:0:(lib-move.c:2078:lnet_handle_find_routed_path()) no route to 10.38.0.250@tcp from 10.5.250.22@o2ib<br>
[Wed Mar 5 15:28:26 2025] LNetError: 28576:0:(lib-move.c:3991:lnet_parse_get()) 10.5.250.22@o2ib: Unable to send REPLY for GET from 12345-10.38.0.250@tcp: -113<br>
<br>
Adding a route to tcp from it’s geo-local router fixed that and we’ve got mounts passing IO. Didn’t seem to need to do the same for clients at all.<br>
<br>
> On Mar 5, 2025, at 2:29</span><span style="font-size:11.0pt;font-family:"Arial",sans-serif"> </span><span style="font-size:11.0pt">PM, John White <jwhite@lbl.gov> wrote:<br>
> <br>
> Oh, so don’t even tell the client about tcp! That seems to have immediately kicked things into place!<br>
> I owe you a beverage of your choice if we ever meet up!<br>
> <br>
> Seriously, the imposter syndrome was getting _bad_ the last few days here.<br>
> <br>
>> On Mar 5, 2025, at 12:05</span><span style="font-size:11.0pt;font-family:"Arial",sans-serif"> </span><span style="font-size:11.0pt">PM, Horn, Chris <chris.horn@hpe.com> wrote:<br>
>> <br>
>> You need LNet routes configured on all nodes. It should look something like this:<br>
>> <br>
>> # pdsh -w n0[0-3] 'lctl list_nids; lctl show_route' | dshbak -c<br>
>> ----------------<br>
>> server<br>
>> ----------------<br>
>> 172.18.2.5@o2ib<br>
>> net o2ib2 hops 2 gw 172.18.2.6@o2ib up pri 0<br>
>> ----------------<br>
>> router1<br>
>> ----------------<br>
>> 172.18.2.6@o2ib<br>
>> 172.18.2.2@tcp<br>
>> net o2ib2 hops 1 gw 172.18.2.3@tcp up pri 0<br>
>> ----------------<br>
>> router2<br>
>> ----------------<br>
>> 172.18.2.7@o2ib2<br>
>> 172.18.2.3@tcp<br>
>> net o2ib hops 1 gw 172.18.2.2@tcp up pri 0<br>
>> ----------------<br>
>> client<br>
>> ----------------<br>
>> 172.18.2.8@o2ib2<br>
>> net o2ib hops 2 gw 172.18.2.7@o2ib2 up pri 0<br>
>> #<br>
>> Chris Horn<br>
>> From: lustre-discuss <lustre-discuss-bounces@lists.lustre.org> on behalf of John White via lustre-discuss <lustre-discuss@lists.lustre.org><br>
>> Date: Wednesday, March 5, 2025 at 1:17</span><span style="font-size:11.0pt;font-family:"Arial",sans-serif"> </span><span style="font-size:11.0pt">PM<br>
>> To: lustre-discuss@lists.lustre.org <lustre-discuss@lists.lustre.org><br>
>> Subject: [lustre-discuss] multi-hop routing<br>
>> Hello folks. I have a rare situation that I’m told some centers are successfully pulling off and am looking for guidance - multi-hop lnet routing.<br>
>> In short, I have 2 distinct o2ib fabrics at disparate geo sites joined by a routed ethernet fabric. I’m looking to use a 2-lnet-router chain to plumb the two o2ib fabrics together.<br>
>> <br>
>> servers on the left, clients on the right<br>
>> o2ib0(10.5.0.0/16) <-> router(o2ib0,tcp0) <-> routed eth (10.37.0.0/16, 10.38.0.0/16) <-> router(tcp0,o2ib2) <-> o2ib2(10.6.0.0/16)<br>
>> <br>
>> I have both sets of routers up but traffic absolutely fails the 2nd hop in either direction (I can `lctl ping` tcp0 from o2ib2 and o2ib0 but no further).<br>
>> <br>
>> I’ve tried adding a route ON the routers, that didn’t help. <br>
>> <br>
>> I’ve tried defining the 2nd hop on the client:<br>
>> options lnet routes="tcp0 10.6.0.[250-251]@o2ib2;\<br>
>> o2ib0 10.37.250.[162-163]@tcp0”<br>
>> <br>
>> but that failed with the following kern message on lnet load:<br>
>> 74067:0:(router.c:644:lnet_add_route()) Cannot add route with gateway 10.37.250.162@tcp. There is no local interface configured on LNet tcp<br>
>> <br>
>> Does anyone have any hints here? It feels like I’m a syntax change or a routing hint away from getting this working.<br>
>> _______________________________________________<br>
>> lustre-discuss mailing list<br>
>> lustre-discuss@lists.lustre.org<br>
>> <a href="https://urldefense.com/v3/__http:/lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org__;!!NpxR!keuGPb7MHd7CQc6Zi_uwIvFahK68FJfbq9MNIXgHpd0W8bi5vOYFHf-IixYY5DiOnJKx0z9-Ht8VqH1ew82XWtaTRaoq$">
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> <br>
> <o:p></o:p></span></p>
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