Re: blocksizes

[Antti Kantee <pooka%cs.hut.fi@localhost>]

On Sun Jan 31 2010 at 22:21:52 +0900, Izumi Tsutsui wrote:
> > Can you please test with your 2K MO?
> 
> It's not easy to test it without working newfs(8) command.
> (if you need hardware I can send the drive and media..)
> 
> > N.B. newfs doesn't yet know how to deduce sector sizes, you need
> > to use the -S option.
> 
> newfs(8) doesn't work even with -S 2048 option.
> (probably it tries to write data at offset not sectorsize aligned)

Apparently makefs -S 2048 works, and the resulting image also works only
when accessed with 2048 byte simulated sector size (fs-utils with ffs
from rump):

pain-rustique:29:~> env RUMP_BLKSECTSHIFT=11 fsu_du -o ro testi2.ffs -sck
rumpblk: using 11 for sector shift (size 2048)
120830  .
120830  total
pain-rustique:30:~> env RUMP_BLKSECTSHIFT=10 fsu_du -o ro testi2.ffs -sck
rumpblk: using 10 for sector shift (size 1024)
fsu_du: Not a directory

But of course makefs uses a file backend, which doesn't care that much
about unaligned writes, so the problem you mention still might exist.