Hi, I've been trying to setup fscache for an NFS share by following various online guides but the client refused to enable the FSC for some reason (client = Debian Unstable, Linux 5.6.0; server = Debian Stable, Linux 4.19.0-8). After a lot of trial and error, I discovered that the caching is enabled as long as the fsid is not zero. Is this expected behavior and, if so, shouldn't it be documented somewhere? Cheers, David Test summary ============ (root@server:/etc/exports.d)$ cat srv.exports # Note: /srv is a separate partition /srv <IPv6 ULA>::/64(sec=krb5:krb5i:krb5p,rw,async,crossmnt,no_subtree_check,root_squash) (root@server:/etc/exports.d)$ exportfs -ra (root@client:~)$ mount -t nfs4 server:/ /mnt/tmp -o sec=krb5,fsc (root@client:~)$ cat /proc/fs/nfsfs/* NV SERVER PORT USE HOSTNAME v4 <server IPv6 addr> 801 1 server NV SERVER PORT DEV FSID FSC v4 <server IPv6 addr> 801 0:70 0:0 no (user@client:~)$ cat /mnt/tmp/srv/somedir/somefile.txt &> /dev/null (root@client:~)$ cat /proc/fs/nfsfs/* NV SERVER PORT USE HOSTNAME v4 <server IPv6 addr> 801 1 server NV SERVER PORT DEV FSID FSC v4 <server IPv6 addr> 801 0:70 0:0 no v4 <server IPv6 addr> 801 0:73 7a26f4d97cd54396:9fffb68912b8d546 yes (root@client:~)$ umount /mnt/tmp (root@client:~)$ mount -t nfs4 server:/srv /mnt/tmp -o sec=krb5,fsc (root@client:~)$ cat /proc/fs/nfsfs/* NV SERVER PORT USE HOSTNAME v4 <server IPv6 addr> 801 1 server NV SERVER PORT DEV FSID FSC v4 <server IPv6 addr> 801 0:73 7a26f4d97cd54396:9fffb68912b8d546 yes (root@client:~)$ umount /mnt/tmp (root@server:/etc/exports.d)$ vi srv.exports (root@server:/etc/exports.d)$ cat srv.exports # Note: /srv is a separate partition /srv <IPv6 ULA>::/64(sec=krb5:krb5i:krb5p,rw,async,crossmnt,no_subtree_check,root_squash,fsid=0) (root@server:/etc/exports.d)$ exportfs -ra (root@client:~)$ mount -t nfs4 server:/ /mnt/tmp -o sec=krb5,fsc (root@client:~)$ cat /proc/fs/nfsfs/* NV SERVER PORT USE HOSTNAME v4 <server IPv6 addr> 801 1 server NV SERVER PORT DEV FSID FSC v4 <server IPv6 addr> 801 0:70 0:0 no (user@client:~)$ cat /mnt/tmp/somedir/somefile.txt &> /dev/null (root@client:~)$ cat /proc/fs/nfsfs/* NV SERVER PORT USE HOSTNAME v4 <server IPv6 addr> 801 1 server NV SERVER PORT DEV FSID FSC v4 <server IPv6 addr> 801 0:70 0:0 no -- Linux-cachefs mailing list Linux-cachefs@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cachefs