Hi Stijn, On 11/06/2015 07:19 PM, Stijn De Weirdt wrote: > hi soumya, > > can you give some details on the clients kernel and nfs protocol used? > > a colleague of mine did some similar tests, and only with nfs 4 > minorversion=1 we get failover/failback working. with 4.0 on recent 7.1 > of 6.7 we have always IO errors on client side.
I am using fedora22 nfs-client (Linux version - 4.2.3-200, Protocol - NFSv4). We do not see any I/O errors though (tried with both NFSv3 & NFSv4 mounts). As mentioned below, it works all well for initial couple of iterations of failover/failback. Thanks, Soumya > > stijn > > On 11/06/2015 01:47 PM, Soumya Koduri wrote: >> Hi, >> >> In a 2-node nfs-ganesha cluster setup, we have noticed that after >> couple of iterations of failover & failback of the IP between those >> nodes, client I/O gets stuck. We have observed this in RHEL 7.1 >> environments (not sure about RHEL 6). While debugging I see that, the >> node which takes over Virtual IP(after couple of iterations) doesn't >> respond(acknowledge) to the client's TCP SYN packet. >> >> Found couple of discussions around it in few forums and I tried >> tuning certain TCP parameters (tcp_timestamp, tcp_window_scaling) as >> mentioned in there. But it did not work. The current work-around we >> are left with (to resume the I/Os) is either * restart nfs-ganesha >> service on the node which has taken over IP, to clear the existing >> established TCP connections. Or * failback the IP by getting the >> original node back online to resume the I/O. >> >> Any ideas on what could be have been the reason for TCP ACK not being >> sent to the TCP SYN packet coming on an existing connection in >> ESTABLISHED state? Any pointers on how to fix that? >> >> Thanks, Soumya >> >> ------------------------------------------------------------------------------ >> >> > _______________________________________________ >> Nfs-ganesha-devel mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/nfs-ganesha-devel >> > > ------------------------------------------------------------------------------ > _______________________________________________ > Nfs-ganesha-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/nfs-ganesha-devel > ------------------------------------------------------------------------------ _______________________________________________ Nfs-ganesha-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/nfs-ganesha-devel
