Great, thank you. zdb confirms what we already sort of suspected: the file is ~12T with only 5.5G of real content. I was aware that ZFS reported on disk size differently, but the fact that this isn't a feature of compression threw me off in the output.
Object lvl iblk dblk dsize dnsize lsize %full type 7 5 16K 128K 5.51G 512 11.1T 0.07 ZFS plain file At any rate, it's still not clear to me how we arrived at this giant (but sparse) file, since the VM and image tools (qemu-img) only consider it to be 10G logical. I'm guessing that the implication is that the bug is with qemu rather than ZFS. My initial concern was that it had been a storage layer corruption, but I guess it's equally plausible that somehow the emulation layer ran wild and just started massively growing the file out of bounds on disk. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to zfs-linux in Ubuntu. https://bugs.launchpad.net/bugs/1766308 Title: inexplicably large file reported by zfs filesystem Status in zfs-linux package in Ubuntu: Triaged Bug description: I have a zfs filesystem containing a single qemu kvm disk image. The vm has been working normally. The image file is only allocated 10G, however today I became aware that the file, when examined from the ZFS host (hypervisor) is reporting an inexplicable, massive file size of around 12T. 12T is larger than the pool itself. Snapshots or other filesystem features should not be involved. I'm suspicious that the file(system?) has been corrupted. root@fusion:~# ls -l /data/store/vms/plexee/ total 6164615 -rw-r--r-- 1 root root 12201321037824 Apr 23 11:49 plexee-root ^^ !!!!!! root@fusion:~# qemu-img info /data/store/vms/plexee/plexee-root image: /data/store/vms/plexee//plexee-root file format: qcow2 virtual size: 10G (10737418240 bytes) disk size: 5.9G cluster_size: 65536 Format specific information: compat: 1.1 lazy refcounts: false refcount bits: 16 corrupt: false root@fusion:~# zfs list rpool/DATA/fusion/store/vms/plexee NAME USED AVAIL REFER MOUNTPOINT rpool/DATA/fusion/store/vms/plexee 5.88G 484G 5.88G /data/store/vms/plexee root@fusion:~# zfs get all rpool/DATA/fusion/store/vms/plexee NAME PROPERTY VALUE SOURCE rpool/DATA/fusion/store/vms/plexee type filesystem - rpool/DATA/fusion/store/vms/plexee creation Mon Mar 26 9:50 2018 - rpool/DATA/fusion/store/vms/plexee used 5.88G - rpool/DATA/fusion/store/vms/plexee available 484G - rpool/DATA/fusion/store/vms/plexee referenced 5.88G - rpool/DATA/fusion/store/vms/plexee compressratio 1.37x - rpool/DATA/fusion/store/vms/plexee mounted yes - rpool/DATA/fusion/store/vms/plexee quota none default rpool/DATA/fusion/store/vms/plexee reservation none default rpool/DATA/fusion/store/vms/plexee recordsize 128K default rpool/DATA/fusion/store/vms/plexee mountpoint /data/store/vms/plexee inherited from rpool/DATA/fusion rpool/DATA/fusion/store/vms/plexee sharenfs off default rpool/DATA/fusion/store/vms/plexee checksum on default rpool/DATA/fusion/store/vms/plexee compression lz4 inherited from rpool rpool/DATA/fusion/store/vms/plexee atime off inherited from rpool rpool/DATA/fusion/store/vms/plexee devices off inherited from rpool rpool/DATA/fusion/store/vms/plexee exec on default rpool/DATA/fusion/store/vms/plexee setuid on default rpool/DATA/fusion/store/vms/plexee readonly off default rpool/DATA/fusion/store/vms/plexee zoned off default rpool/DATA/fusion/store/vms/plexee snapdir hidden default rpool/DATA/fusion/store/vms/plexee aclinherit restricted default rpool/DATA/fusion/store/vms/plexee canmount on default rpool/DATA/fusion/store/vms/plexee xattr on default rpool/DATA/fusion/store/vms/plexee copies 1 default rpool/DATA/fusion/store/vms/plexee version 5 - rpool/DATA/fusion/store/vms/plexee utf8only off - rpool/DATA/fusion/store/vms/plexee normalization none - rpool/DATA/fusion/store/vms/plexee casesensitivity sensitive - rpool/DATA/fusion/store/vms/plexee vscan off default rpool/DATA/fusion/store/vms/plexee nbmand off default rpool/DATA/fusion/store/vms/plexee sharesmb off default rpool/DATA/fusion/store/vms/plexee refquota none default rpool/DATA/fusion/store/vms/plexee refreservation none default rpool/DATA/fusion/store/vms/plexee primarycache all default rpool/DATA/fusion/store/vms/plexee secondarycache all default rpool/DATA/fusion/store/vms/plexee usedbysnapshots 0 - rpool/DATA/fusion/store/vms/plexee usedbydataset 5.88G - rpool/DATA/fusion/store/vms/plexee usedbychildren 0 - rpool/DATA/fusion/store/vms/plexee usedbyrefreservation 0 - rpool/DATA/fusion/store/vms/plexee logbias latency default rpool/DATA/fusion/store/vms/plexee dedup off default rpool/DATA/fusion/store/vms/plexee mlslabel none default rpool/DATA/fusion/store/vms/plexee sync standard default rpool/DATA/fusion/store/vms/plexee refcompressratio 1.37x - rpool/DATA/fusion/store/vms/plexee written 5.88G - rpool/DATA/fusion/store/vms/plexee logicalused 7.94G - rpool/DATA/fusion/store/vms/plexee logicalreferenced 7.94G - rpool/DATA/fusion/store/vms/plexee filesystem_limit none default rpool/DATA/fusion/store/vms/plexee snapshot_limit none default rpool/DATA/fusion/store/vms/plexee filesystem_count none default rpool/DATA/fusion/store/vms/plexee snapshot_count none default rpool/DATA/fusion/store/vms/plexee snapdev hidden default rpool/DATA/fusion/store/vms/plexee acltype off default rpool/DATA/fusion/store/vms/plexee context none default rpool/DATA/fusion/store/vms/plexee fscontext none default rpool/DATA/fusion/store/vms/plexee defcontext none default rpool/DATA/fusion/store/vms/plexee rootcontext none default rpool/DATA/fusion/store/vms/plexee relatime off default rpool/DATA/fusion/store/vms/plexee redundant_metadata all default rpool/DATA/fusion/store/vms/plexee overlay off default root@fusion:~# dpkg -l | grep zfs ii libzfs2linux 0.6.5.6-0ubuntu20 amd64 Native OpenZFS filesystem library for Linux ii zfs-dkms 0.6.5.6-0ubuntu20 amd64 Native OpenZFS filesystem kernel modules for Linux ii zfs-doc 0.6.5.6-0ubuntu20 all Native OpenZFS filesystem documentation and examples. ii zfs-initramfs 0.6.5.6-0ubuntu20 all Native OpenZFS root filesystem capabilities for Linux ii zfs-zed 0.6.5.6-0ubuntu20 amd64 OpenZFS Event Daemon (zed) ii zfsutils-linux 0.6.5.6-0ubuntu20 amd64 Native OpenZFS management utilities for Linux root@fusion:~# uname -a Linux fusion 4.13.0-38-generic #43~16.04.1-Ubuntu SMP Wed Mar 14 17:48:43 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/zfs-linux/+bug/1766308/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
