How have you deleted the plan9.iso file? If you have used rm(1) or fossilcons(4) remove, the blocks should be properly unallocated from Fossil. But if you used fossilcons(4) clri for example, you have to manually reclaim the abandoned storage with clre and bfree, with the help of fossil/flchk or fossilcons(4) check.
See the following illustration: # our current empty fossil main: df main: 40,960 used + 1,071,710,208 free = 1,071,751,168 (0% used) # we copy a file on fossil, then remove it properly % cp /386/9pcf /n/fossil main: df main: 3,661,824 used + 1,068,089,344 free = 1,071,751,168 (0% used) main: remove /active/9pcf main: df main: 57,344 used + 1,071,693,824 free = 1,071,751,168 (0% used) # we copy a file on fossil, then remove it with clri % cp /386/9pcf /n/fossil main: df main: 3,661,824 used + 1,068,089,344 free = 1,071,751,168 (0% used) main: check checking epoch 1... check: visited 1/130829 blocks (0%) fsys blocks: total=130829 used=447(0.3%) free=130382(99.7%) lost=0(0.0%) fsck: 0 clri, 0 clre, 0 clrp, 0 bclose main: clri /active/9pcf main: df main: 3,661,824 used + 1,068,089,344 free = 1,071,751,168 (0% used) main: check checking epoch 1... check: visited 1/130829 blocks (0%) fsys blocks: total=130829 used=447(0.3%) free=130382(99.7%) lost=0(0.0%) error: non referenced entry in source /active[0] fsck: 0 clri, 1 clre, 0 clrp, 0 bclose # we identify the abandoned storage and reclaim it with bfree term% fossil/flchk -f fossil.img | sed -n 's/^# //p' clre 0x5 0 term% fossil/flchk -f fossil.img | sed -n 's/^# bclose (.*) .*/bfree \1/p' bfree 0x7 bfree 0x8 [...] main: clre 0x5 0 block 0x5 0 40 000000001FF420002900000000000000003691B900000000000000000000000071875E60000001A1 main: bfree 0x7 label 0x7 0 1 1 4294967295 0x71875e60 main: bfree 0x8 label 0x8 1 1 1 4294967295 0x71875e60 [...] main: check checking epoch 1... check: visited 1/130829 blocks (0%) fsys blocks: total=130829 used=7(0.0%) free=130822(100.0%) lost=0(0.0%) fsck: 0 clri, 0 clre, 0 clrp, 0 bclose main: df main: 3,661,824 used + 1,068,089,344 free = 1,071,751,168 (0% used) Note that it doesn't update c->fl->nused, reported by df. -- David du Colombier
