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Dear List,

I have one last little problem with setting up an cluster. My gfs Mount will hang as soon as I do an iptables restart on one of the nodes..

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Undoubtedly someone else with more experience with GFS will give you an answer, but to me this makes me think ip_conntrack stuff gets cleared out and sessions have to reestablish themselves.

Ray

Ray,

Thanks for your fast answer and getting me into the right direction. This sounds like a possible solution, but I have no clue how to fix it. I

googled

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already a lot on ip_conntrack + gfs, but don't see a possible solution coming up.

Can someone/you please help me a little bit more with the issue?

Thanks a lot! Sven

Are your GFS mounts and your cluster on different sides of the firewall?

Maybe you can do something simple like a tunnel between the clusters and

the

mounts. Should be easier and safer than punching holes in the firewall. Or

put

a separate subnet or vlan just for the GFS traffic.

Uhm... I have the cluster running on a different vlan then my ISCSI traffic. Is that a problem? I would not like to put my cluster communication on the other vlan since thats iscsi dedicated now.

I have now figured out that it isn't the restarting IP tables causing the trouble, but the issue is as follows:

- Calling Group_tool dump This will cause groupd to run at 100% cpu. Dooing a strace on this process tells me its dooing some poll in an infinite loop: poll([{fd=1, events=POLLIN}, {fd=2, events=POLLIN}, {fd=7, events=POLLIN}, {fd=8, events=POLLIN}, {fd=9, events=POLLIN}, {fd=10, events=POLLIN}, {fd=12, events=POLLIN}, {fd=14, events=POLLIN}, {fd=18, events=POLLIN}, {fd=17, events=POLLIN}, {fd=20, events=POLLIN}, {fd=21, events=POLLIN, revents=POLLNVAL}, {fd=-1}], 13, -1) = 1

- Calling Group_tool dump gfs This will cause gfs_controld to run at 100% cpu. Exactly the same as the groupd (strace): poll([{fd=2, events=POLLIN}, {fd=3, events=POLLIN}, {fd=6, events=POLLIN}, {fd=7, events=POLLIN}, {fd=8, events=POLLIN}, {fd=11, events=POLLIN}, {fd=12, events=POLLIN, revents=POLLNVAL}, {fd=12, events=POLLIN, revents=POLLNVAL}], 8, -1) = 2

Sometimes my Mount will hang, but sometimes it will just continue normally. I can imagine this has to do with the amount of data going to the gfs Mount.

So I guess it isn't really an iptables problem.. But im trying to debug that a little bit more as well..

Any clues?

Thanks!! Sven