Re: file system shenanigans (was: Re: [PLUG] ELF Init section)

[qumak <qumak@home.com>]

Le Mardi  5 Juin 2001 08:00, vous (gabriel rosenkoetter) avez écrit :
> V-derived systems, this defaults to 512b blocks. On all the Linux
> systems I've used, it seems to default to 1K blocks. On every system
> trying to be POSIX compliant, du -k reports in 1K blocks.
>
> Does this imply that the ext2 file systems on all the Linux systems
> I've used are using 1K blocks on disk? I doubt it. It's just what
> whoever wrote GNU's du decided was appropriate (because it's easier
> for a human to understand? I guess, but only because we've become
> power-of-(about)-ten-byte centric in the 90s).
>
> I'm still distantly curious about why the default block sizes for
> ext2 are what they are (does this make ext2 deal with a wider
> variety of disks better with less user intervention? seems like a
> program-that's-trying-to-be-too-smart problem would come up awfully
> quickly that way), but I guess I'm more curious about what workloads
> call for what block sizes (and fragment sizes, and cylinders per
> group, and so forth). Any conventional or experimental wisdom on
> that?

well - this is what i see with du, would suggest against the 1K rule:
[qumak@XXXX qumak]$ echo 'test' > sample
[qumak@XXXX qumak]$ du -b sample
4096    sample
[qumak@XXXX qumak]$ wc -c sample
      5 sample
[qumak@XXXX qumak]$


this to me would suggest that du can be only as specific as the block size of 
your filesystem (the -b option looks for bits, by the way - much like wc -c, 
except of course the 4091 extra non-existant bits ;))

I'm assuming the fifth byte is in fact the first, being a magic number, but 
i'm probably wrong, it could be something else entirely ;)

--qumak(james)


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