🚀 go-pugleaf

In article <13615@cbmvax.commodore.com> jesup@cbmvax (Randell Jesup) writes:
>
> 	We'll report the amount of space left, but neither we nor Unix (nor
> I suspect VMS) guarantee a specific number of blocks used to store a file.
> Unix is slightly less variable, due to preallocation of inodes, but even it
> varies (bsd storing of small files in partial blocks, etc).

That's fine.  I wasn't looking for any "guarantees".  Is it possible that you
can do the same for the actual number of blocks (or some variant thereof) used
by a file via fib_NumBlocks or a similar mechanism?


> 	The caller should be aware that since it doesn't know exactly the
> algorithms used by the filesystem to store the data, there's no way to be 
> certain of your interpretation of whether the file will fit (even if nothing
> else is happening).

True, but it can be a real good "sanity check" at times.  No guarantees tho.


> 	It's fairly simple to write a file of null/garbage data of the given
> length, and see whether it succeeds (or under 2.0 use SetFileSize to get the
> filesystem to do it for you - even faster).

2.0 sounds better and better all the time!  Thanks for all the "goodies"!


> >When and where will
> >all this "good stuff in 2.0" be documented (for the masses)?
> 
> 	Get the Atlanta Devcon notes from CATS.

I wasn't aware that they were available yet?  What's the cost ... my check is
all made out except for that item ... :-)


> 	That doesn't work if the allocation sizes are variable (there are
> other gotcha's as well).  I think my previous statement stands: the size
> reported is a reasonable approximation, but there can be no guarantee of
> correlation with other values/objects.

I've run into one (pathass), as I mentioned in a previous posting, but that
was won a "logical" psuedo-device.  What real devices vary their allocations
in the way you're suggesting?


Thanks for all the info on this stuff Randell ... it is appreciated, and may
keep a few of us from falling in a deep, dark hole in the future!

/kim

-- 
UUCP:  kim@uts.amdahl.com   -OR-   ked01@juts.ccc.amdahl.com
  or:  {sun,decwrl,hplabs,pyramid,uunet,oliveb,ames}!amdahl!kim
DDD:   408-746-8462
USPS:  Amdahl Corp.  M/S 249,  1250 E. Arques Av,  Sunnyvale, CA 94086
BIX:   kdevaughn     GEnie:   K.DEVAUGHN     CIS:   76535,25