Hey, I've been running xfstests on a v5.12-rc3 kernel using a swapfile: ubuntu@edfu|~ > cat /etc/fstab # /etc/fstab: static file system information. # # Use 'blkid' to print the universally unique identifier for a # device; this may be used with UUID= as a more robust way to name devices # that works even if disks are added and removed. See fstab(5). # # <file system> <mount point> <type> <options> <dump> <pass> # / was on /dev/sdb1 during curtin installation /dev/disk/by-uuid/f2c4df25-b55c-4d1b-95fa-059f72ef86eb / ext4 defaults 0 0 /swap.img none swap sw 0 0 where my rootfs is ext4: ubuntu@edfu|~ > findmnt | grep -i ext4 / /dev/sdb1 ext4 rw,relatime In addition to the /dev/sdb disk I have three other disks attached: ubuntu@edfu|~ > lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT loop0 7:0 0 55.5M 1 loop /snap/core18/1988 loop1 7:1 0 69.9M 1 loop /snap/lxd/19188 loop2 7:2 0 70.4M 1 loop /snap/lxd/19647 loop3 7:3 0 32.3M 1 loop /snap/snapd/11107 loop4 7:4 0 32.3M 1 loop /snap/snapd/11402 sda 8:0 0 931.5G 0 disk sdb 8:16 0 223.6G 0 disk └─sdb1 8:17 0 223.6G 0 part / sdc 8:32 0 279.5G 0 disk sdd 8:48 0 931.5G 0 disk I'm using two of them /dev/sdc and /dev/sdb for xfstests: ubuntu@edfu|~/src/git/xfstests > cat local.config # Ideally define at least these 4 to match your environment # The first 2 are required. # See README for other variables which can be set. # # Note: SCRATCH_DEV >will< get overwritten! export FSTYP=xfs export TEST_DEV=/dev/sdc export TEST_DIR=/mnt/test export SCRATCH_DEV=/dev/sdd export SCRATCH_MNT=/mnt/scratch when the system gets under load during test runs I assume it sometimes swaps and so sometimes I see the following messages pop up: > sudo journalctl | grep -i swapon Mar 21 00:00:58 edfu kernel: swapon: file has shared extents Mar 21 02:25:52 edfu kernel: swapon: file has unallocated extents Mar 21 21:38:12 edfu kernel: swapon: file has shared extents Mar 22 00:16:03 edfu kernel: swapon: file has unallocated extents Mar 23 11:49:46 edfu kernel: swapon: file has shared extents Mar 23 12:34:38 edfu kernel: swapon: file has unallocated extents I don't know enough about swapfiles to make any deep observations but I wonder what this can be caused by and whether this is something to worry about. Christian
