Hi, We've got a number of ext4 fs on a LVM logical volume. When they get 'full' (0 available space according to df, normal user can't place any more files), or ideally slightly before, we use lvm's lvextend command with the -r option, which invokes fsadm, which I guess in turn uses resize2fs. Recently we extended a ~1.9TB filesystem by 20GB, however afterwards df reported 0 available bytes. The LV had been increased and running resize2fs reported that the fs was already the full size of the device. tune2fs showed fewer free blocks than reserved blocks. Despite this, normal users could create files on the filesystem (via nfs) and copy several GB of data on without trouble. Forced fsck found no issues, though with fragcheck enabled it reported plenty of blocks that were not the expected length (and 9.4% non-contiguous). Further, copying data on did not appear to change the reported free nodes from tune2fs, though we didn't attempt to completely fill the drive. We've since manually lowered the reserved blocks count below the free blocks count in case the inverted situation was somehow causing this behaviour. Is this a bug? Normally once df reports 0 available normal users are not able to add more data, regardless of remaining reserved space. If it's expected behaviour can someone clarify what's happening? This is the current tune2fs, reserved blocks was previously about 24924508, free blocks was already around 17315627 when we lowered the reserved blocks: tune2fs 1.42.9 (28-Dec-2013) Filesystem volume name: <none> Last mounted on: /mnt/research/ftd Filesystem UUID: 0e4e6c45-a11b-43ff-84c8-ed21fbbde460 Filesystem magic number: 0xEF53 Filesystem revision #: 1 (dynamic) Filesystem features: has_journal ext_attr resize_inode dir_index filetype needs_recovery extent 64bit flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize Filesystem flags: signed_directory_hash Default mount options: user_xattr acl Filesystem state: clean Errors behavior: Continue Filesystem OS type: Linux Inode count: 126623744 Block count: 506472448 Reserved block count: 13107200 Free blocks: 17315627 Free inodes: 124820983 First block: 0 Block size: 4096 Fragment size: 4096 Group descriptor size: 64 Reserved GDT blocks: 795 Blocks per group: 32768 Fragments per group: 32768 Inodes per group: 8192 Inode blocks per group: 512 Flex block group size: 4096 Filesystem created: Wed Jun 24 15:05:23 2015 Last mount time: Thu Jul 18 13:23:59 2019 Last write time: Thu Jul 18 13:23:59 2019 Mount count: 1 Maximum mount count: -1 Last checked: Thu Jul 18 13:21:25 2019 Check interval: 0 (<none>) Lifetime writes: 12 TB Reserved blocks uid: 0 (user root) Reserved blocks gid: 0 (group root) First inode: 11 Inode size: 256 Required extra isize: 28 Desired extra isize: 28 Journal inode: 8 Default directory hash: half_md4 Directory Hash Seed: a5f445de-e71e-4601-9014-c82b8c8ec89e Journal backup: inode blocks -- imalone http://ibmalone.blogspot.co.uk
