On Mon, Jan 05, 2009 at 08:23:53PM +0100, Oliver Fromme wrote: > ... > > pool10(7.1-RC1)[36] dumpfs -m /dev/da1s1d > > # newfs command for /dev/da1s1d (/dev/da1s1d) > > newfs -O 2 -U -a 8 -b 16384 -d 16384 -e 2048 -f 2048 -g 16384 -h 64 -m 8 > -o time -s 879031908 /dev/da1s1d > > This seems to be a bug in dumpfs(8). It simply prints > the value of the fs_size field of the superblock, which > is wrong. > > The -s option of newfs(8) expects the available size in > sectors (i.e. 512 bytes), but the fs_size field contains > the size of the file system in 2KB units. This seems to > be the fragment size, but I'm not sure if this is just > coincidence (the docs state that it's the size in blocks, > but this is misleading because the blocksize is usually > different; the default is 16K). > > So, dumpfs(8) needs to be fixed to perform the proper > calculations when printing the value for the -s option. > Unfortunately I'm not sufficiently much of a UFS guru > to offer a fix. My best guess would be to multiply the > fs_size value by the fragment size (measured in 512 byte > units), i.e. multiply by 4 in the most common case. > But I'm afraid the real solution is not that simple.
Empirically, I find that -- at least in the case in question -- using the superblock's dsize, multiplied by 2, gets the correct result: Filesystem 1024-blocks Used Avail Capacity Mounted on /dev/da1s1d 1702753030 2744 1566530044 0% /b Extract from "ffsinfo -l 1": ===== END CYLINDER SUMMARY TOTAL ===== time ufs_time_t 1231206211 size int64_t 0x000000003464f664 dsize int64_t 0x0000000032bef983 csaddr ufs2_daddr_t 0x0000000000000bb8 A bit of messing about with dc(1): g1-35(6.4-S)[4] dc 16 i 32BEF983 2 * p 1702753030 g1-35(6.4-S)[5] Then again, it isn't especially common in my experience to want a file system that occupies an amount of space different from the amount that is available for the file system (e.g., the partition size). So if that were wanted, providing a way to have dumpfs(8) merely make no claims whatsoever about or for the newfs(8) "-s" parameter might be adequate. My circumvention of piping the result through sed(1) accomplishes that, at some additional complexity and potential confusion. Peace, david -- David H. Wolfskill da...@catwhisker.org Depriving a girl or boy of an opportunity for education is evil. See http://www.catwhisker.org/~david/publickey.gpg for my public key.
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