cd /sys/src/cmd/venti/words; rc dumpvacroots 
arena='arenas.0' [802816,537673728)
	version=5 created=1523538014 modified=1523547845 sealed
	score=99d252fd65d81548c87b03b7ab76eb876a8a0edb
	clumps=457,656 compressed clumps=456,496 data=3,748,432,956 compressed data=507,993,756 disk storage=536,826,084
arena='arenas.1' [537673728,1074544640)
	version=5 created=1523547845 modified=1523556367 sealed
	score=8eeba98876868c05b5066751f7a7a3e313903ca0
	clumps=452,575 compressed clumps=451,422 data=3,706,948,286 compressed data=508,309,759 disk storage=536,821,984
arena='arenas.2' [1074544640,1611415552)
	version=5 created=1523556367 modified=1523564861 sealed
	score=e5bc6d24b01db217946c2df5722face77911d006
	clumps=455,531 compressed clumps=454,385 data=3,731,342,084 compressed data=508,124,549 disk storage=536,823,002
arena='arenas.3' [1611415552,2148286464)
	version=5 created=1523564861 modified=1523573508 sealed
	score=93bce3d136e513afba64376ea73cde667a21395e
	clumps=457,434 compressed clumps=456,285 data=3,746,777,560 compressed data=508,010,808 disk storage=536,829,150
arena='arenas.4' [2148286464,2685157376)
	version=5 created=1523573508 modified=1523582005 sealed
	score=28da2f57339fdffa17f5aaf219222a448cd22089
	clumps=450,622 compressed clumps=449,468 data=3,690,895,610 compressed data=508,433,287 disk storage=536,822,473
arena='arenas.5' [2685157376,3222028288)
	version=5 created=1523582005 modified=1523589997 sealed
	score=2b9538852681480bc02219ffa02c68e8ac4763a9
	clumps=445,031 compressed clumps=443,852 data=3,644,394,847 compressed data=508,793,843 disk storage=536,830,796
arena='arenas.6' [3222028288,3758899200)
	version=5 created=1523589997 modified=1523598277 sealed
	score=e28fbff1912faa848b35a32e9ef5351e46dc8164
	clumps=463,529 compressed clumps=462,214 data=3,794,362,685 compressed data=507,623,574 disk storage=536,825,901
arena='arenas.7' [3758899200,4295770112)
	version=5 created=1523598277 modified=1523650919
	clumps=411,495 compressed clumps=409,964 data=3,362,300,328 compressed data=287,629,324 disk storage=313,553,509
vac:2554653c676db639e27afc2350c24531ecbe0b6d
vac:61a98c331e6511d3fc386f09ee8292a8f5f18d0d
vac:72ad4600fdca387f6ba53a39847679cbd8a8420c
vac:ad98484c7f859c9fd58c732f3e40acdfd9b8953e
vac:9b7934d874dc498a2b4e696e24f5fc5c4edcf465
vac:8e7fed90b3388a697da45fb6efd7dcdf497ee6cf
vac:5c1bb334c0e40b080c245409d0a9ea8b73e9d074

cd /sys/src/cmd/venti/words; fossil/last /dev/bkp/fossil
vac:5c1bb334c0e40b080c245409d0a9ea8b73e9d074

cd /srv; fossil/flfmt -v 5c1bb334c0e40b080c245409d0a9ea8b73e9d074 /dev/bkp/fossil
fs header block already exists; are you sure? [y/n]: y
dce40de7ab4726393f6f4a4c3fb8a5b47977f0f5
fcb69c05629bd6ebf2eccdd0a9f06e38765834cd
c2d68849f6124419703f012d67b6f39b38de0f88
fossil/flfmt: bad root: no qidSpace


cd /mnt/term/home/j/dev/apps/plan9/custom/9front-patches/venti; rc vacchain.rc  'vac:5c1bb334c0e40b080c245409d0a9ea8b73e9d074'
vac:5c1bb334c0e40b080c245409d0a9ea8b73e9d074
venti/read 5c1bb334c0e40b080c245409d0a9ea8b73e9d074 16
vac:8e7fed90b3388a697da45fb6efd7dcdf497ee6cf
venti/read 8e7fed90b3388a697da45fb6efd7dcdf497ee6cf 16
vac:9b7934d874dc498a2b4e696e24f5fc5c4edcf465
venti/read 9b7934d874dc498a2b4e696e24f5fc5c4edcf465 16
vac:ad98484c7f859c9fd58c732f3e40acdfd9b8953e
venti/read ad98484c7f859c9fd58c732f3e40acdfd9b8953e 16
vac:72ad4600fdca387f6ba53a39847679cbd8a8420c
venti/read 72ad4600fdca387f6ba53a39847679cbd8a8420c 16
vac:61a98c331e6511d3fc386f09ee8292a8f5f18d0d
venti/read 61a98c331e6511d3fc386f09ee8292a8f5f18d0d 16
vac:2554653c676db639e27afc2350c24531ecbe0b6d
venti/read 2554653c676db639e27afc2350c24531ecbe0b6d 16
vac:da39a3ee5e6b4b0d3255bfef95601890afd80709
venti/read da39a3ee5e6b4b0d3255bfef95601890afd80709 0
block da39a3ee5e6b4b0d3255bfef95601890afd80709 too short
cd /mnt/term/home/j/dev/apps/plan9/custom/9front-patches/venti; fossil/flfmt -v vac:da39a3ee5e6b4b0d3255bfef95601890afd80709 /dev/bkp/fossil
fs header block already exists; are you sure? [y/n]: y
fossil/flfmt: corrupted root: vtrootunpack
cd /mnt/term/home/j/dev/apps/plan9/custom/9front-patches/venti; fossil/flfmt -v vac:da39a3ee5e6b4b0d3255bfef95601890afd80709 /dev/bkp/fossil
fs header block already exists; are you sure? [y/n]: y
fossil/flfmt: bad score 'vac:da39a3ee5e6b4b0d3255bfef95601890afd80709'