Just had the weirdest problem with a new disk, NFS shares and LVM. Scenario: Two computers - server and desktop Fitting a new 3TB drive into server, and my USB adapter doesn't handle it. Only shows 800 GB disk. Server has all four SATA ports are in use, can't install new disk beside existing ones to copy data. I want to keep server running for now, so popping the failing drive and using USB adapter on that would work, but then we'd not have this story. So I connect the new drive to desktop internal SATA port, and it shows as 2.7 TB. Good enough.
New drive is organised as /dev/sdc1 being a PV, and there are two LVs created, 350 GB for backup and 2 TB for mythtv. There's 380 GB in unallocated extents, just cos I can. Both LVs are formatted as ext4. Filesystem 1K-blocks Used Available Use% Mounted on /dev/mapper/threeTB-mythtv 2145296304 31711256 2006210868 2% /x/mythtv /dev/mapper/threeTB-backuppc 382284292 5758368 357389412 2% /x/backuppc I want to copy file permissions etc, so a NFS mount seems appropriate. On desktop /etc/exports contains /x 2400:6900:2000:1::/64(rw,sync,no_root_squash,subtree_check) And on desktop exportfs returns /x 2400:6900:2000:1::/64 On server I mount the exported share for desktop:/x Everything looks good, I can see the two directories all well and good. server:/x# ll total 8 drwxr-xr-x 2 root root 4096 Feb 24 19:50 backuppc drwxr-xr-x 5 root root 4096 Feb 24 19:51 mythtv desktop:/x# ll total 8 drwxr-xr-x 2 root root 4096 Feb 24 19:50 backuppc drwxr-xr-x 5 root root 4096 Feb 24 19:57 mythtv I start synching data with this server:/# rsync -avH /myth1 /x/mythtv/ but after a moment, there are no files in /x/mythtv/ on desktop??? desktop:/x# du -sh * 20K backuppc 20K mythtv server:/x# du -s * (yes okay I missed the -h) 4 backuppc 0 boomofo 564384 mythtv At this point I noticed that blocks were decreasing on my root volume Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda1 58503812 38638360 16934720 70% / /dev/sda1 58503812 39202812 16370268 71% / /dev/sda1 58503812 39518088 16054992 72% / I stop the rsync with ^C at this point. On desktop when I unmounted /x/mythtv, then all the files were visible in /x/mythtv *on the root partition.*** The client machine (server) could read and write them happily, but the host (desktop) couldn't see the files because something was mounted on top. Perhaps NFS wasn't aware of the LVs mounted one level on from the root of an export (share) Finally, if I export the two LVs as separate exports, and mount each separately on the remote machine, everything works as expected. Conclusion - NFS doesn't like exporting a tree of mounts. Further work - whether NFS dislikes all mounts, or just LVM mounts. But my TV drive is reporting imminent fail, so I'm going to deal to that. Comments? -- Criggie
_______________________________________________ Linux-users mailing list [email protected] http://lists.canterbury.ac.nz/mailman/listinfo/linux-users
