Strange inode count with /dev/vzfs

I am using Plesk on an Ubuntu 14.04 server and experiencing some strange problems: I checked mount: /dev/vzfs on / type reiserfs (rw,usrquota,grpquota) Then stat /dev/vzfs: stat: cannot stat ‘/dev/vzfs’: No such file or directory Then df: Filesystem 1K-blocks Used Available Use% Mounted on /dev/vzfs 209715200 177877760 31837440 85% / none 2097152 4 2097148 1% /dev none 4 0 4 0% /sys/fs/cgroup none 419432 104 419328 1% /run none 5120 0 5120 0% /run/lock none 2097152 4 2097148 1% /run/shm none 102400 0 102400 0% /run/user And df -i: Filesystem Inodes IUsed IFree IUse% Mounted on /dev/vzfs 18446744070447236696 18446744069415584328 1031652368 100% / none 524288 61 524227 1% /dev none 524288 1 524287 1% /sys/fs/cgroup none 524288 118 524170 1% /run none 524288 12 524276 1% /run/lock none 524288 2 524286 1% /run/shm none 524288 1 524287 1% /run/user The inode counts are terribly close to the 64 bit arithmetic limit, so I suspect an integer overflow to cause the problems. Other users cannot write to files thanks to quota limitations, even though I never set any specific quotas. I don't know how to debug and/or solve this problem, can someone help me with this? --- Update: I disabled quotas in the VPS settings of my provider, and mount now indicates that the type of the filesystem changed: /dev/vzfs on / type vzfs (rw,relatime) I also created the file in /dev using mknod, stat /dev/vzfs now says File: ‘/dev/vzfs’ Size: 0 Blocks: 0 IO Block: 4096 block special file Device: 9eh/158d Inode: 2347445354 Links: 1 Device type: 0,ba Access: (0644/brw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root) Access: 2017-07-11 16:59:42.471740071 +0200 Modify: 2017-07-11 16:59:42.471740071 +0200 Change: 2017-07-11 16:59:42.471740071 +0200 Birth: - df -i still shows this: Filesystem Inodes IUsed IFree IUse% Mounted on /dev/vzfs 18446744070447246304 18446744069415584345 1031661959 100% / none 524288 62 524226 1% /dev none 524288 1 524287 1% /sys/fs/cgroup none 524288 120 524168 1% /run none 524288 12 524276 1% /run/lock none 524288 2 524286 1% /run/shm none 524288 1 524287 1% /run/user And there are still error messages: -bash: cannot create temp file for here-document: Disk quota exceeded --- I originally posted this question [at ask ubuntu](https://askubuntu.com/questions/935102/strange-inode-count-with-dev-vzfs) but it was suggested to post it here. --- Update: I restored a backup from a few days ago and the server seems to be running without problems. inode counts are back to normal, but I am pretty close to the inode limit set by my hosting provider, so that might be the problem.