Am 03.10.22 um 13:39 schrieb Jeff Layton: > On Sun, 2022-10-02 at 14:35 +0200, Manfred Schwarb wrote: >> Hi, >> >> I have 2 boxes connected with 2 network cards each, one >> crossover connection and one connection via LAN. >> I want to use the crossover connection for backup, >> so I want to be able to select exactly this wire when >> doing my NFS backup transfers. Everything interconnected via NFS4.1 >> and automount. >> >> Now the thing is, if there is an already existing connection >> via LAN, I am not able to select the crossover connection, >> there is some session reuse against my will. >> >> automount config: >> /net/192.168.99.1 -fstype=nfs4,nfsvers=4,minorversion=1,clientaddr=192.168.99.100 / 192.168.99.1:/ >> /net2/192.168.98.1 -fstype=nfs4,nfsvers=4,minorversion=1,clientaddr=192.168.98.100 / 192.168.98.1:/ >> >> mount -l: >> 192.168.99.1:/data on /net/192.168.99.1/data type nfs4 (...,clientaddr=192.168.99.100,addr=192.168.99.1) >> 192.168.99.1:/data on /net2/192.168.98.1/data type nfs4 (...,clientaddr=192.168.99.100,addr=192.168.99.1) >> >> As you see, both connections are on "192.168.99.1:/data", and the backup runs >> over the same wire as all user communication, which is not desired. >> This even happens if I explicitly set some clientaddr= option. >> >> Now I found two workarounds: >> - downgrade to NFS 4.0, clientaddr seems to work with it >> - choose different NFS versions, i.e. one connection with >> minorversion=1 and the other with minorversion=2 >> >> Both possibilities seem a bit lame to me. >> Are there some other (recommended) variants which do what I want? >> >> It seems different minor versions result in different "nfs4_unique_id" values, >> and therefore no session sharing occurs. But why do different network >> interfaces (via explicitly set clientaddr= by user) not result in different >> "nfs4_unique_id" values? >> >> Thanks for any comments and advice, >> Manfred > > That sounds like a bug. We probably need to compare the clientaddr > values in nfs_compare_super or nfs_compare_mount_options so that it > doesn't match if the clientaddrs are different. > > As a workaround, you can probably mount the second mount with > -o nosharecache and get what you want. Indeed, nosharecache works. But the man page has some scary words for it: "This is considered a data risk". Thanks, Manfred
