=== step 0: environment ===
DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #0: Thu Jul  2 06:02:54 UTC 2026     root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC  x86_64
hw.physmem: 4257873920
vm.swap_size: 1048512
=== step 1: create 200-page (819200 byte) swap backing file ===
swapfile size before: 819200
=== step 2: attach vn0 and swapon ===
swapon: adding /dev/vn0 as swap device
vm.swap_size delta after swapon: 192 pages (expect +192 = 768KB published; only 136 pages/544KB truly exist in the allocatable stripes)
--- swapinfo: vn0 claims 2048 512-blocks (1MB) on an 800KB file ---
Device          512-blocks     Used    Avail Capacity  Type
/dev/vbd0s1b       8388608        0  8388608     0%    Interleaved
/dev/vn0              2048        0     2048     0%    Interleaved
Total              8390656        0  8390656     0%
=== step 3: churn anonymous memory to drive pageout into the phantom tail ===